It Came From Above

(X is your life total minus 1.)
It Came From Above can't be countered.
Tap all permanents. Then, create a legendary 10/10 colorless Angel Horror creature token with flying, haste, and indestructible named Alteria Omnus.
"As the Omnus descended from on high, every knee bent, each head bowed, and our hearts sunk to oblivion." - Tebwin, Skyspeaker