Celtic Heroes

I have figured out when Corrupted Touch gets cast (sort of). It seems to be only when Tank is in range of the Elemental Nuke (Drake). When standing at spikes, tank will never get Corrupted unless drake is pulled to the opposite side of Diothu. However, if the Tank goes in to taunt/warcry/bash etc, a...

Does anyone know what causes Dino to cast this skill? On Taranis, Dino seems to either cast it once every couple minutes, or spams it every 20 seconds.