The lack of a general CoW thread is fairly concerning. So here it is.

Full ability set, resistances and AI can be found on the Wiki.

Feel free to correct me if there are any wrong/misleading informations or some new tips that needs to be added.

Overview

Stats

• Race: Stone, Machina

• Can be fully broken

• Resistance:

AI Summary

• Counter healing magic (Curaja etc.) with 20% self-heal.
• Can be diseased. Self-cleanse disease every 3 turns.
• Threshold is at 75%, 50%, 25% where he sets up mitigation and ATK/MAG/accuracy buff.
• The turn after any threshold, casts 99% AoE full break.
• Will do HUGE morale fill if not hit by lightning every turn
• Most AoE damage is lightning (physical or hybrid) or earth elemental (magical or hybrid)
• *Uses AoE physical with Petrify every 3rd turn
• *Uses AoE 200% imperil & Paralyze every 2nd turn (lightning or earth above 50% HP, both if below)
• Self-break DEF by 95% if hit with lightning 5 turns in a row while below 50%

*: Every n turn
Above 50% HP: Used on turn n, 2n, 3n
Below 50% HP: Used every 2nd/3rd turn since crossing the threshold

Team Building (0 EX Modifier)

• [banner unit of the week] is very effective
• Bring protection against Petrify and Paralyze
• Preferred element is Lightning with Water/Light being slightly less effective
• If planning to use Morale-scaling unit, you have to deal lightning damage every turn
• Omnicover is recommended due to both physical/magical AoE is being used
• For single clears, bursting from 100% is recommended
• For high score clears, bursting under 50% HP after the boss self-break is recommended