Epochrasite

This creature enters with three +1/+1 counters on it if you didn't cast it from your hand.
When this creature dies, exile it with three time counters on it and it gains suspend. (At the beginning of its owner's upkeep, they remove a time counter. When the last is removed, they may cast this card without paying its mana cost. It has haste.)

Illuminor Szeras

Secrets of the Soul — {T}, Sacrifice another creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Timeline Culler

Haste
You may cast this card from your graveyard using its warp ability.
Warp—{B}, Pay 2 life. (You may cast this card from your hand or graveyard for its warp cost. If you do, exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Electropotence

Whenever a creature you control enters, you may pay {2}{R}. If you do, that creature deals damage equal to its power to any target.

Lucius the Eternal

Haste
Armour of Shrieking Souls — When Lucius the Eternal dies, exile it and choose target creature an opponent controls. When that creature leaves the battlefield, return this card from exile to the battlefield under its owner's control.

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Squee, the Immortal

You may cast this card from your graveyard or from exile.

Gollum, Patient Plotter

When Gollum leaves the battlefield, the Ring tempts you.
{B}, Sacrifice a creature: Return this card from your graveyard to your hand. Activate only as a sorcery.

Cult Conscript

This creature enters tapped.
{1}{B}: Return this card from your graveyard to the battlefield. Activate only if a non-Skeleton creature died under your control this turn.

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Scourge of Nel Toth

Flying
You may cast this creature from your graveyard by paying {B}{B} and sacrificing two creatures rather than paying its mana cost.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.