Aplan Mortarium
Plane — Alfava Metraxis
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 token isn't a creature until end of turn."
Helge C. Balzer
Doctor Who (WHO)
• #568Rulings
As the triggered ability of the Alien Angel token resolves, it continues to be an artifact but will stop being both an Alien and an Angel until it becomes a creature again.
(wotc • 2023-10-13)
If an opponent casts a creature spell with flash while the token is attacking or blocking, the token is removed from combat because it stops being a creature. However, any creatures that it was blocking are still considered blocked.
(wotc • 2023-10-13)
Rulings
As the triggered ability of the Alien Angel token resolves, it continues to be an artifact but will stop being both an Alien and an Angel until it becomes a creature again.
(wotc • 2023-10-13)
If an opponent casts a creature spell with flash while the token is attacking or blocking, the token is removed from combat because it stops being a creature. However, any creatures that it was blocking are still considered blocked.
(wotc • 2023-10-13)