Slaughter Specialist

When this creature enters, each opponent creates a 1/1 white Human creature token.
Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Archfiend of the Dross

Flying
This creature enters with four oil counters on it.
At the beginning of your upkeep, remove an oil counter from this creature. Then if it has no oil counters on it, you lose the game.
Whenever a creature an opponent controls dies, its controller loses 2 life.

Clackbridge Troll

Trample, haste
When this creature enters, target opponent creates three 0/1 white Goat creature tokens.
At the beginning of combat on your turn, any opponent may sacrifice a creature of their choice. If a player does, tap this creature, you gain 3 life, and you draw a card.

Metamorphic Alteration

Enchant creature
As this Aura enters, choose a creature.
Enchanted creature is a copy of the chosen creature.