I haven't decided when I will revamp my other analyses, but I thought I should write some analysis to test out the new analysis template I thought of, and since my first analysis here is an Igursus analysis (a Mountain monster), writing a Cryotan analysis for my return made sense. I also thought I should show it to everyone to see your feedback on it. Unfortunately, I do not have this monster, so I will probably miss some of its unique interactions. Without further ado...

Hello everyone and welcome to my 207th analysis, this time featuring Cryotan.
Overview: When you look at his stats, you'll think Cryotan should definitely be a tank that functions in a similar way to Ouros; staying alive and killing enemies off by the Death Counter of Euboea, a Mega Freeze move that sets the target on a 3 turn Death Counter, effectively giving them 1 turn to move without other monsters' interception. Coupled with his Mountain trait allowing him to protect himself from some of the most common deny methods, you have yourself a monster who's difficult to keep down. While stall is a plausible strategy - and at times will be the go-to move to utilize - the true power of Cryotan lies in the move Boösaule Montes. This move Mega Freezes the entire enemy team, and with the insane power level of Monsters nowadays, 2 turns is more than enough to greatly dismantle, or even kill, the enemy team. An AOE deny move like this might suggest a fast denier style, but this is an incorrect deduction since Boösaule Montes has a Stamina cost of 250, which necessitates the usage of Stamina Runes, which in turn prevents him from running 3 Speed Runes (there is a way to remedy this, but I'll get into that later, plus it is situational). Thus, the better way(usually) to use Cryotan is as something like a tanky secondary denier: Mega Freezing the enemy team with Boösaule Montes while dealing with pesky monsters using Euboea, and giving yourself Taunt if need be, though stall always remains an option especially against Possession-heavy teams.

In Water: Being a tank means resisting the moves here allows Cryotan to live longer. Plus, attackers are relatively uncommon and Freeze is the most commonly used deny method in Water, which makes Cryotan even better. However, secondary denier might find all the Stamina Drain annoying since it will prevent the usage of Boösaule Montes - still, Euboea can be used in conjunction with Skadi, making staller Cryotan a great choice. Ironically, an opposing Cryotan is one of the biggest threats due to Euboea threatening to stop his stally antics, so make sure to bring debuff removal against teams with Cryotan. In both Attack and Defense, Cryotan will put in work among Water monsters, but it can be a better idea to use stall for Defense since monsters with Possession, like Kihaku, can use Boösaule Montes against you to devastate your team, whereas stall only has Euboea to look out for.

In the Winter Book: Stall Cryotan has a field day here, since this book is teeming with Water monsters that are either attackers that can't really do much to him, or deniers that use Freeze as their deny method which Cryotan is immune to, but secondary denier Cryotan might be annoyed by the amount of Freeze immunity. There is unfortunately some buff/debuff control here but it is very scarce compared to the other books he's in. Putting him in Defense is very useful here, but it depends on the other rulings.

In Evil Legions: Now this is a different story. The sheer amount of powerful monsters here of all kinds of roles gives Cryotan trouble - especially all the buff/debuff control that goes on in here. Unless you have a good way to deny the opposing Evil Legions monster, I don't recommend using any slow monster in this book, but thankfully Cryotan has Boösaule Montes to make use of the denied enemies. Use Cryotan in Attack mode only, because there are so many things that can counter him if you put him in Defense - if you must, use the secondary denier as stall won't work with all the counter options.

In Families: Possession could be trouble for Cryotan, but it comes down to a coin flip because he does have Self moves to dodge said status ailment, so it's not the worst. Buff/Debuff control still exists thanks to things like Saika and Kassia, and Sunblast can activate his CDs, which devastates Cryotan. He's not a bad choice, but it again depends on whether you can deny the things that threaten him or not - if you can, he'll do his job by getting Boösaule Montes off. The same Attack/Defense suggestion from Evil Legions applies here as well.

-Boösaule Montes/Elysium
Runes: 1 Stamina (at least Level V) 1 Speed 1 Life or 2 Stamina 1 Life (if you have runes at Level IV or below)/ 2 Life 1 Speed
Mutant Rune options: Speed&Life, Stamina&Speed, Life&Speed
Relics: (The leftmost relic is of the least priority while the rightmost relic is of the highest priority. Some relic rarities might not be listed if they don't do much.)
Soul Armor - Heavy Duty Armor - Atum's Armor/Nebotus' Armor/Thetys' Armor | Exhausting Trap/Cold Trap - Pestilence Trap - Ruby Trap/Mantis Claws Trap

Build Explanation:
Boösaule Montes is a pivotal move in Cryotan's arsenal since it allows him to excellently perform the role of secondary denier. Skadi allows him to do something after Boösaule Montes has been used - you will almost always have enough Stamina to use any of your other moves after using this, not to mention it gives the AI a way out of Possession. Euboea puts tough enemies like Ouros on a Death Timer, and if they are able to be Mega Frozen, this will give them just 1 turn to move. Lastly, Olympus allows Cryotan to function as a tank by receiving all single target moves and essentially doubling his Life. Alternatively, a stall based approach can be used by forgoing Boösaule Montes in the first slot for Elysium. This gives Cryotan a better shot at dealing with Possession monsters and capitalizes more on his tank role by making him ridiculously hard to kill when combined with Olympus (essentially giving you a 200% Life Shield), and this moveset can be used if the attack target has many monsters that can deal with Freeze effects or you feel like the battle will be a stall war, which is a battle Cryotan will almost always win.
For the Boösaule Montes set, 1 Stamina, Speed and Life will give him enough Stamina to use said move (if your Stamina Rune is at least Level V), make him not too slow and improve the power of Olympus. If your Runes are low leveled, you'd have to go with 2 Stamina 1 Life. The Elysium set instead utilizes 2 Life 1 Speed, which makes Cryotan extremely tanky. As for Mutant Runes, they focus on getting as much extra Life and Speed as possible.
As for Relics, things that either keep you alive longer or try to deny things that attack you are chosen for the Armor and Trap slots with the exception of the Pestilence trap, which should preferably be used with the Boösaule Montes set. Whichever options are most important among Relics of the same rarity is dictated by the enemy team.

Team Options: AOE CD Deactivators like Captain Copperbeard can be used to deactivate the CDs of all allies: with Skadi and Euboea, Cryotan can target all enemies one by one each time he gets a turn this way - Captain Copperbeard can also be a primary denier with his AOE Stun. For more Teammate options, check out this article.

Countering Cryotan: Removing debuffs from your team saves the target of Euboea. If you get lucky with Possession, both Euboea and especially Boösaule Montes will have devastating effects on Cryotan's team. For more Counter options, check out this article.