Hapless Researcher

Sacrifice this creature: Draw a card, then discard a card.

Careful Study

Animate Dead

Enchant creature card in a graveyard
When this Aura enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with this Aura." Return enchanted creature card to the battlefield under your control and attach this Aura to it. When this Aura leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to that card's mana value.

Unmask

You may exile a black card from your hand rather than pay this spell's mana cost.
Target player reveals their hand. You choose a nonland card from it. That player discards that card.

Akroma, Angel of Wrath

Flying, first strike, vigilance, trample, haste, protection from black and from red

Putrid Imp

Discard a card: This creature gains flying until end of turn.
Threshold — As long as there are seven or more cards in your graveyard, this creature gets +1/+1 and can't block.

Phantom Nishoba

Trample
This creature enters with seven +1/+1 counters on it.
Whenever this creature deals damage, you gain that much life.
If damage would be dealt to this creature, prevent that damage. Remove a +1/+1 counter from this creature.