Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Anger

Haste
As long as this card is in your graveyard and you control a Mountain, creatures you control have haste.

Primeval Protector

This spell costs {1} less to cast for each creature your opponents control.
When this creature enters, put a +1/+1 counter on each other creature you control.

Riveteers Ascendancy

Whenever you sacrifice a creature, you may return target creature card with lesser mana value from your graveyard to the battlefield tapped. Do this only once each turn.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Bygone Colossus

Warp {3} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Venom, Lethal Protector

Menace, trample, haste
Whenever Venom attacks, you may sacrifice another creature. If you do, draw X cards, then you may put a permanent card with mana value X or less from your hand onto the battlefield, where X is the sacrificed creature's mana value.

Eddie Brock

When Eddie Brock enters, return target creature card with mana value 1 or less from your graveyard to the battlefield.
{3}{B}{R}{G}: Transform Eddie Brock. Activate only as a sorcery.

Eddie Brock // Venom, Lethal Protector

Diamond Weapon

This spell costs {1} less to cast for each permanent card in your graveyard.
Reach
Immune — Prevent all combat damage that would be dealt to Diamond Weapon.

Honest Rutstein

When Honest Rutstein enters, return target creature card from your graveyard to your hand.
Creature spells you cast cost {1} less to cast.