Aplan Mortarium [Planechase]

Byzantium Radiation — At the beginning of your upkeep, put an exposure counter on Aplan Mortarium. Then you lose life equal to the number of exposure counters on it.
Whenever chaos ensues, create two 2/2 black Alien Angel artifact creature tokens with first strike, vigilance, and “Whenever an opponent casts a creature spell, this permanent isn’t a creature until end of turn.”