Gilded Drake

Flying
When Gilded Drake enters, exchange control of Gilded Drake and up to one target creature an opponent controls. If you don't or can't make an exchange, sacrifice Gilded Drake. This ability still resolves if its target becomes illegal.

Well of Ideas

When Well of Ideas enters, draw two cards.
At the beginning of each other player's draw step, that player draws an additional card.
At the beginning of your draw step, draw two additional cards.

Braids, Conjurer Adept

At the beginning of each player's upkeep, that player may put an artifact, creature, or land card from their hand onto the battlefield.

Denethor, Stone Seer

When Denethor, Stone Seer enters, scry 2.
{3}{R}, {T}, Sacrifice Denethor: Target player becomes the monarch. Denethor deals 3 damage to any target.

Worldfire

Exile all permanents. Exile all cards from all hands and graveyards. Each player's life total becomes 1.