Wither reduces the attack of every figure in a stack by 2 + death shard. And the game has a corruption spell which turns any shards into death shards.
In a recent game I played Ceresa on a large map and had some 20 shards.
Sure, with 20 shards you should be powerful. On a tactical map I believe everything is fine, the spell has a casting time of 1 and can be resisted.
But on the strategic map, the spell costs just 24 mana to cast, isn't resistable and despite it's description saying it has a 3 turn cooldown time, it can be cast as often as you want.
Is there a bug with the cooldown?