The spell applied from the shaman epic does not do any damage for three ticks after landing. I've loaded the latest spell file to be sure it isn't something on my end.
After three ticks it starts its normal damage sequence at about 11-12 damage, increasing in damage as the spell holds like it should.
Also, any chance for a little shaman love with a damage boost to the epic clicky?

It's alright if it gets a chance to ramp up but with lowered mob health the pet gets em before it goes too far. And the mobs with enough health to take a full cycle typically have a health pool so large the spell does minimal damage compared to poisons or a well equipped pet.
Really appreciate the 1 second cast on it though!