Mass of Remains's power is equal to the total number of permanent cards you own in your graveyard and in exile.
Spellcharge 3

Target creature you control gets +2/+1 until end of turn. It fights up to one target creature you don't control.

Devoid
Target creature gains double strike until end of turn. Put a +1/+1 counter on that creature if it's colorless.

When Maven of Fear enters, mill two cards.
Maven of Fear gets +2/+1 and has menace as long as six or more cards are in your graveyard.

Whenever another creature you control enters, Mayuk Claw-Sage gets +1/+0 and gains trample until end of turn.

Target creature gains indestructible until end of turn. Teach it lifelink.

When Meeting of the Elites enters, create a tapped Treasure token.
You've sacrificed a nonland permanent this turn.

Whenever you draw your second card each turn, scry 1 then put a +1/+1 counter on Melancholic Oracle.

{T}: Target player mills two cards.
{2}, {T}: Target player mills four cards.
{4}, {T}: Draw two cards. Activate this ability only if a player has ten or more cards in their graveyard.

{T}: Target player mills two cards.
{T}: Add one mana of any color. Spend this mana only to cast spells from your graveyard or activate abilities of cards in your graveyard.

{1}{U/R}, {T}: Tap target creature, then gain control of it until end of turn. Activate only as a sorcery.

Harness
Exile the top three cards of your library. Cast a spell with mana value X or less from among them without paying its mana cost.

Exile the top three cards of your library. You may play up to two of those cards this turn.

Dragon spells and Rift spells you cast cost {1} less to cast.

{R}, {T}: Copy target activated ability you control. You may choose new targets for the copy.

Whenever you cast a noncreature spell, surveil 1.
If you would draw a card while your library has no cards in it, you may instead put a card you own from exile or outside the game into your hand.

Return target creature or enchantment to its owner's hand. If that permanent's controller has eight or more cards in their graveyard, its owner puts it on the top or bottom of their library instead.

Surveil 2, then choose an instant or sorcery card in your graveyard. You may cast it this turn. If that spell would be put into your graveyard this turn, exile it instead.

Whenever Mistcall Mariner becomes tapped, up to one target creature gets -2/-0 until end of turn.

{1}{B}, Pay 2 life: Mob Hangman dares 4.
Whenever Mob Hangman attacks, if it's a Rebel, each opponent sacrifices a creature or planeswalker unless they discard a card.

Whenever a creature you control becomes a Rebel, creatures you control get +1/+0 until end of turn.
{2}{R}: Mob Instigator dares 4.

When Moonlit Meditation enters, draw three cards, then put two cards from your hand on top of your library.
{1}{U}, Sacrifice Moonlit Meditation: Shuffle up to three target cards from your graveyard into your library.

Ward {1}
Whenever Morbid Bloomer deals combat damage, you may pay {1}. When you do, return up to one other target permanent card from your graveyard to your hand.

Vehicles you control can't be blocked by Humans.
Crew 3
During your main phase, you may sacrifice a creature or exile a creature card from your graveyard rather than pay Morkfar's crew cost.

Put two +1/+1 or loyalty counters on target creature or planeswalker. It gains lifelink until end of turn.