Ob Nixilis of the Black Oath

If The Prismatic Piper is your commander, choose a color before the game begins. The Prismatic Piper is the chosen color. Partner (You can have two commanders if both have partner.)

When you cast this spell, if you have fewer than seven cards in hand, draw cards equal to the difference. Menace Discard a card with mana value X: Counter target spell with mana value X.

Changeling (This card is every creature type.) As Morophon enters, choose a creature type. Spells of the chosen type you cast cost WUBRG less to cast. This effect reduces only the amount of colored mana you pay. Other creatures you control of the chosen type get +1/+1.

Annihilator 3 (Whenever this creature attacks, defending player sacrifices three permanents of their choice.) This creature can't be blocked except by three or more creatures.

When you cast this spell, exile two target permanents. Indestructible Whenever Ulamog attacks, defending player exiles the top twenty cards of their library.

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.) This creature attacks each combat if able.

Outlast 1W (1W, T: Put a +1/+1 counter on this creature. Outlast only as a sorcery.) Each creature you control with a +1/+1 counter on it has first strike.

When Alharu enters, put a +1/+1 counter on each of up to two other target creatures. Whenever a nontoken creature you control with a +1/+1 counter on it dies, create a 1/1 white Spirit creature token with flying. Partner (You can have two commanders if both have partner.)