Squee, Goblin Nabob

At the beginning of your upkeep, you may return Squee, Goblin Nabob from your graveyard to your hand.

Fearsome Werewolf

Menace (This creature can't be blocked except by two or more creatures.)
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Fearful Villager

Menace (This creature can't be blocked except by two or more creatures.)
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Fearful Villager // Fearsome Werewolf

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Witty Roastmaster

Alliance — Whenever another creature you control enters, Witty Roastmaster deals 1 damage to each opponent.

Confusion in the Ranks

Whenever an artifact, creature, or enchantment enters, its controller chooses target permanent another player controls that shares a card type with it. Exchange control of those permanents.

Guild Artisan

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, you create two Treasure tokens." (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Warstorm Surge

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

Squee, the Immortal

You may cast Squee, the Immortal from your graveyard or from exile.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Pandemonium

Whenever a creature enters, that creature's controller may have it deal damage equal to its power to any target of their choice.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Norin the Wary

When a player casts a spell or a creature attacks, exile Norin the Wary. Return it to the battlefield under its owner's control at the beginning of the next end step.

Reinforced Ronin

Haste
At the beginning of your end step, return Reinforced Ronin to its owner's hand.
Channel — {1}{R}, Discard Reinforced Ronin: Draw a card.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)