Steel Fortress Formula

FOR L/D ONLY

December 17th 2020

My goal with this guide is that by the time you are done reading this your understanding for this dungeon will be somewhat to significantly improved as well as you knowing all your options to use as of today. Now since one of the last updates, they made every boss do the exact same skills on every level, aka Steel Fortress B1 through B10 use all the same skills, same AI, same everything. Of course the stats go up as well as resistance which can get tricky. As your rune quality goes up, so does your floor level but the strategy never changes. Every dungeon basically has a formula to have the best chance of beating it safely.

Steel Fortress boss gets defense buff and a shield worth 10% of his HP EVERY time he is hit as shown in above picture. He also gets attack power buff and crit rate buff every time he gets a turn and for every beneficial effect he has, he will take 20% less damage and gain 20% more attack bar, so 80% less damage and 80% more attack bar if he gets all 4 of his effects. Also, he can stun you every 5ft turns you take as you can see in the picture above and can apply defense break. I am sure you can see the importance of beneficial effect block here to survive and to even deal any kind of damage. If for some reason you do not have ANY beneficial effects blockers yet, I DO NOT recommend even trying this, just skip this for now OR maybe you can try to over power lower floors with just pure damage.

The picture above shows where his attack back is with 1 buff. The picture below shows how much attack bar he gains from his tower. Now if he had all 4 buff's that's 100% attack bar as the tower gives +20% then an additional +20% PER buff. Stressing how important ben block and strip is.

There is a basic formula for almost literally every aspect of the game

You need 1-2 damage dealers, 1-2 support monsters may that be healers or buffers or cleansers and you need some kind of crowd control monster that can preferably AOE control to keep your team alive and of course hopefully there is a good leader skill in there to furthermore buff your stats. So, how does one counter this as L/D only? Lets go through it step by step with the most viable monsters available to most.

(I won’t be going over every monsters entire skillsets, just what is relevant for each section.)

To block his effects we have:

Eirgar (Dark Vampire Lord) S2 Beneficial effect block
Zinc (Dark Living Armor) S3 Beneficial effect block
Glinodon (Light Lizardman) S2 Beneficial block
Gina (Dark Witch) S2 Beneficial block
Of course there are several other good Nat 4 and Nat 5 options but I won’t go through those as I think you get the idea by now.

For his defense break and stun we have:

The defense break is not very threatening if your controlling the boss attack bar.

Veromos (Dark Ifrit) has passive AOE cleanse every turn.
Fran (Light Fairy Queen) has S3 AOE immunity to prevent def break and stuns
Light Homunculus has S2 AOE immunity to prevent def break and stuns, not as reliable since only 1 turn but also has a path for S3 AOE cleanse and def buff which is very good.
Shushu (Light Howl) has S3 AOE immunity for 2 turn IF after her heal everyone is full HP. Not as reliable unless you have a super tanky team or a backup healer that heals before her.
Dona (Light Penguin Knight) has S3 AOE Cleanse, not recommended here as there are much better options.
Haken (Dark Bearman) has S2 AOE cleanse, not recommended here as there are much better options.
Jamie (Dark Bounty Hunter) has S3 AOE Cleanse, not a terrible choice as he can also provide good damage and attack buff.
Of course there are several other good Nat 4 and Nat 5 options but I won’t go through those as I think you get the idea by now.

To prevent him from getting turns out of beneficial block:

Loren (Light Cow girl) She is our superstar for attack bar control, will deny his turns very nicely keeping everything going smoothly, she is vital to a consistent run.
Kroa (Dark Harg) He adds speed buff to the whole team making everyone's turn cycle much faster and has a pretty good attack bar control S2 so is worth mentioning here.
Groteau (Light Minotaur) His S2 if crits steals all the enemies attack bar and then boosts his own by the amount stolen, could be used here.
Sia (Light Harpu) her S3 has a multi hit attack bar reduction but it's on a 5 turn cool down, not recommended here.
Elpuria (Light Serpent) has S2 that has a low chance to significantly reduce attack bar x3 but not reliable, I do not recommend this monster here.
Driller (Light Frankenstein) has S2 AOE attack bar reduction but it's not very significant and not really recommended here.
Fran (Light Fairy Queen) her S1 reduces attack bar plus she healing and attack buff and immunity is invaluable here, highly recommended.
Basalt and Marble (Dark and Light Battle Mammoths) both have an AOE attack bar reduction skill but it's not enough to really control anything.
Of course there are several other good Nat 4 and Nat 5 options but I won’t go through those as I think you get the idea by now.

Healers:

Shushu (Light Howl) can actually single and AOE heal quite nicely and bring situational immunity but has low stats since she is a Nat 2.
Jansson (Light Viking) has a poor AOE heal but bring excellent attack bar increase (Budget Verdehile).
Teon (Light Garuda) is an underrated monster if I've ever seen one. Good AOE heal, can rez, turn cycling, stuns, what can't this birdy do.
Ahman (Light Bearman) has an excellent heal every single turn. If built correctly, solid choice.
Tien Quin (Light Drunken Master) between his S2 and S3 healing he is a good healer as well but built for more aggressive team and better rune quality.
Fran (Light Fairy Queen) everyone's favorite. AOE healing and attack buff, single target healing and cleanse, attack break, this queen can be used literally everywhere in the game.
Belladeon (Light Inugami) has a great AOE healing, great attack bar boosting and a reliable strip and defense break, very good choice.
Eshir (Light Werewolf) has a moderate AOE healing with AOE speed buff and reliable strip.
Rasheed (Dark Epikion Priest) is now a reasonable choice as a healer/cleanse/buff extender since her recent buff but there are better choices.
Basalt (Dark Battle Mammoth) has a good AOE healing and AOE defense buffer.
Light Homunculus is a good secondary healer with a variety of buffs depending on skills chosen.
Of course there are several other good Nat 4 and Nat 5 options but I won’t go through those as I think you get the idea by now.

Leaders:

When it comes to leaders in Cairos you want more Speed/ Attack Power/ Critical Rate/Health Points or Defense. You should be runeing Accuracy into your monsters and don’t waste your time with Resistance.

Attack power leaders:

Prom (Light Grim Reaper) 30% attack power to light only.
Loren (Light Cow Girl) 18% attack power to all.
Elsharion (Light Ifrit) 33% attack power to all.
Shamman (Light Griffon) 30% attack power to light only.
Hellea (Dark Harpy) 30% attack power to dark only.
Thrain (Dark Grim Reaper) 30% attack power to dark only.
Cassie (Dark Cow Girl) 18% attack power to all.
Eirgar (Dark Vampire Lord) 38% attack power in dungeons.

Speed leaders:

Walkers (Light Bounty Hunter) 23% speed to light only.
Fran (Light Fairy Queen) 10% speed to all.
Rumicus (Light Charger Shark) 23% speed to light only.
Lucien(Light Elven Ranger) 15% speed to all.
Janssen (Dark Viking) 10% speed to all.
Calicus (Dark Charger Shark) 23% speed to dark only.

Health points leaders:

Teon (Light Garuda) 17% health points to dungeons.
Groggo (Light Golem) 30% health points to light only.
Grotau (Light Minotaur) 30%health points to light only.
Baekdu (Light Beast Hunter) 21% health points to dungeons.
Dona (Light Penguin Knight) 30%health points to light only.
Lusha (Light Warbear) 15% health points to all.
Kumae (Dark Yeti) 25% health points to dark only.
Kamatau (Dark Minotaur) 30% health points to dark only.
Kuna (Dark Penguin Knight) 30% health points to dark only.
Veromos (Dark Ifrit) 33% health points to all.

Defense leaders:

Sia (Light Harpu) 25% defense to light only.
Ahman (Light Bearman) 30% defense to light only.
Marble (Light Battle Mammoth) 30% defense to light only.
Seren (Dark Harpu) 25% defense to dark only.
Haken (Dark Bearman) 30% defense to dark only.
Basalt (Dark Battle Mammoth) 30% defense to dark only.

Critical rate leaders:

Eludain (Light Inferno) 23% critical rate to light only.
Shren (Light High Elemental) 23% critical rate to light only.
Drogan (Dark Inferno) 23% critical rate to dark only.
Jumaline (Dark High Elemental) 23% critical rate to dark only.

Note: These are all the leaders available for F2P but some are definitely better than others. I just don’t want to limit your creativity :)

Of course there are several other good Nat 4 and Nat 5 options but I won’t go through those as I think you get the idea by now.

Crowd control:

In my opinion there is no specific crowd control needed for this dungeon. The crystal towers don’t apply defense break or cc so the odds are that you will kill them much sooner than they will kill you. Plus you will have a healer with you keeping you safe. However I do recommend the following stats for things to run smoothly.

General stat requirements:

To be put simply, you want your weakest units to be able to take 3 hits from the crystal towers because lets say you get odd RNG and your units only have enough time to kill 2 of the towers but there are still 3 crystals left to have a turn each. So now one of your units is about to get smacked by 3 towers. See the logic? In any case, these are the stats you should have at the BARE minimum for Steel Fortress B10 for things to go well. Keep in mind these calculations are WITH MAX glory towers / MAX guild bonuses but NO leader skills.

17000 Health points (If you have more HP then this then you can have a bit less defense).
1000 Defense (If you have more defense than this then you can have a bit less hp).
170 Speed (To ensure you get a turn before the 169 speed enemy monsters).
25% Accuracy needed on monsters that apply (Like Eirgar for beneficial block and Loren for attack bar control and strip). Not sure why the developers made the accuracy needed so much lower than other dungeons but just take it! :P

Due to popular demand, I also have rough calculations on required stats WITHOUT ANY towers / guild bonuses or leader skills.

19500 - 21500 Health points (Depends how high the monsters base Health points are)
1200 - 1350 Defense (Depends how high the monsters base defense is)
185 - 195 Speed (Depends how high the monsters base speed is)
Note: These calculations are without a leader skill as calculating all leader skill potentials would take forever. So if you just can't match the health points requirement then use a HP leader to close the gap as an example.

If all your towers and guild bonuses are about half way then you need about half way in between the two stat requirements I previously mentioned. The most important thing is that all your monsters move before any of the enemies. In these 2 following pictures you will see what your team might look like after 2 tower attacks. My Kro is just above the minimum stat requirements. You can see that you can take hits from 2 towers and even survive the third, which gives you enough time to dispatch of the rest before anyone on your team gets killed.

Yup, those are the only stats you really need to know for now. Obviously, your support units and healers are at least this tanky but probably tankier by the time you are ready for B10. Your damage dealers however, are a bit more tricky to rune since you want to squeeze every ounce of damage stats in as you can. SO, for damage dealers, meet the above requirements then everything else is damage stats! IF you just cant seem to get those tankier stats on your damage dealers, consider using an HP/ Def leader, having a unit on shield runes or equipping artifacts that have a minus dark damage reduction sub stat. IF you have just tried everything and it just seems a bit out of your league, I recommend staying in B9 a bit longer till you find a few more rune upgrades on your current team as the stat requirements (including speed for trash only) are roughly 10%- 15% less overall). Damage dealers should have at least 1500 Attack/Defense, 70% crit rate and 150% crit damage at the bare minimum.

Summary:

Now that you see what you need and your options are laid before you, now you get to pick what you want to use. Yes, there are a lot of options, yes there are overall better options than others and yes with good enough runes literally any combination is possible to beat it with as long as you follow the formula. Just remember that you need 1 or 2 or even 3 monsters that can apply beneficial block effect for this for consistency or else, if ben block dosen't get applied, you will get no where with damage on the boss and although you might live, the run will take a very long time.

There are many nat 4 and 5 monsters I did not touch on since you ether need to have gotten the Hall of Heroes or need to have summoned it. I will leave it to your digression to look at your uncommon monsters skill sets and see if they fit better than any of the F2P options. I will however answer any questions, do more focused guides, advanced guides and expand on the options as time goes on. This is mostly so you understand the dungeon without me telling you exactly what you should be doing, more like just guiding you, thus this GUIDE ;)

Theory crafting:

Now, lets go over some of the most commonly used monsters, this applies to ALL levels depending on rune quality.

Lets say your trying a more aggressive team to start. Note: I did not go over damage dealers as the sky is the limit since anyone can really be runed to deal descent damage. I will let you experiment but I will give advice of course :) When building a team in almost every situation you want your Attack bar controls/ Defense breakers/ Buffers/ Strippers to move before any damage dealers. In this dungeon your kind of at the mercy of one of your units landing beneficial effect block before you will see any progress. If the boss ends up with all 4 of his buffs, your in big trouble!

Eirgar (L) (one of best offence dungeon leaders possible with attack buff and vampire buff for sustain as well as epic single target debuffs including Ben block!)
2A Kro (not rivalled by many in the single target damage output department and his team up skill will help your ben block appliers turn cycle faster to increase consistency)
Loren (defense break setup almost guaranteed and insane attack bar reducer which will help a lot here to prevent boss from getting turns out of ben block!
Belladeon (great AOE healing and attack bar increase, defense breaker and stripper!)
2A Gorgo (good AOE damage plus crowd control and AOE attack break with minor attack bar reduction)

On paper this team makeup looks good! Now, lets say you keep getting to final boss safely but once you are there Eirgar seems to keep missing the application of ben block and is getting stunned here and there which really slows down the rate the boss is getting killed at, in fact sometimes it takes foreverrrr! On the plus side, you not really dying very easily, maybe you have too much safety? Well, let's fix the ben block problem by simply adding ANOTHER ben block unit! Let's try this new team and see how it goes shall we? Let's also add Fran, maybe her immunity will help with the stuns!

Eirgar
2A Kro
Loren
Zinc (for the additional ben block)
Fran (for immunity mostly)

Now this team makeup seems really good right? Well, your not wrong, however, it seems to be overkill having 2 attack buffers and both Eirgar and Zinc apply attack break, so is Fran really needed? You notice that once you get to boss, his defense buff seems to take Loren forever to strip sometimes... Maybe let's add Belladeon back for the strip! (Eshir is more consistent however!)

Eirgar
2A Kro
Loren
Zinc
Belladeon (adeed back for the strip)

Ahhh, now it looks great! Things are running smoothly, ben block is often applies quickly between the two of them and your no longer having issues with the defense buff not getting stripped! Huston, we have a winner. Now you can farm this reliably and it can only get better as your runes get better.

Notice this team has 1-2 Damage dealers, 1-2 supports/healers and crowd control. If you are still failing you are too high on the levels and need to go down a notch and increase rune quality once more. You do need accuracy to land those beneficial effects blockers and to control his attack bar, without those 2 things, your going to have a hard time winning.

I hope this all somewhat makes sense and that it helped, if it helped at least one person then it was worth it! In the future I will be making speed team guides!

Here is a what a smooth run should roughly look like