Kathru, World Razer

Flying, trample
Whenever Kathru, World Razer attacks you may choose up to three permanents, for each pay {r}{r}. Destroy each of those permanents, for each permanent chosen this way that permanents controller choose another permanent you control of the same type, destroy those permanents.
No cave, no stronghold, no castle, no fortress is safe from his incandescent blaze.