Question about skeletal storm mages

Heya,

I have a question about skeletal storm mages and their debuff. In order to get the debuff on enemies, do you have to actually use their ability, or do they passively shock the enemy to get the lightning debuff.

IE, can I just summon a few storm mages and let them run around shocking enemies and bosses, or do you actively have to wait for a minion to die in order to use their ability and cast the lighting to shock the enemy?

Hi, they apply shock whenever they land a critical hit which applies also for theit auto-attack. But even with 100% increased crit chance to minions from tree it looks like the chance is something about 10-15%.

Thanks for the reply. So it may be worth it on hard bosses, but probably not for general map clear as stuff dies so quickly anyway.