So I just made the Gravedigger up in my head.
He’s cool looking with a hood and a shovel and a “pest doctor mask”.
Turn all green gems to brown (as if digging grass leaving soil) and turn all brown gems to skulls.
If this triggers an extra turn (as if there are somewhere more than 3 skulls in a row) then he has a 50% chance to resurrect* a dead troop.
*resurrected troops are poisoned and diseased,
will poison or disease the enemy on skull attack
The Gravedigger himself is immune to poison and disease thanks to his second trait (and pest mask).