Nethroi, Apex of Death

As this creature enters, choose odd or even. (Zero is even.) This creature has protection from each mana value of the chosen quality.

Mutate 2B/RWW (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.) Double strike Whenever this creature mutates, it deals 4 damage to target creature or planeswalker an opponent controls and you gain 4 life.

Your opponents can't cast spells from anywhere other than their hands.

Rielle gets +1/+0 for each instant and sorcery card in your graveyard. Whenever you discard one or more cards for the first time each turn, draw that many cards.

Mutate 1W/URR (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.) Flying, first strike Whenever this creature mutates, you may cast target noncreature card with mana value 3 or less from your graveyard without paying its mana cost.

Whenever you cast a noncreature spell, draw a card.

(T: Add U, R, or W.) This land enters tapped. Cycling 3 (3, Discard this card: Draw a card.)

At the beginning of combat on your turn, choose a kind of counter at random that this creature doesn't have on it from among flying, first strike, deathtouch, hexproof, lifelink, menace, reach, trample, vigilance, and +1/+1. Put a counter of that kind on this creature.