Whenever Assembled Alphas blocks or becomes blocked by a creature, Assembled Alphas deals 3 damage to that creature and 3 damage to that creature's controller.
7/13/2016 The triggered ability triggers once for each creature blocking or blocked by Assembled Alphas. The ability resolves and deals damage to that creature before combat damage is dealt. If that damage destroys all creatures blocking Assembled Alphas, Assembled Alphas doesn’t become unblocked.
7/13/2016 The triggered ability deals damage to the creature’s controller even if the creature isn’t dealt damage, perhaps because it has left the battlefield or because the damage was prevented.