Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Gamble

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Double Vision

Whenever you cast your first instant or sorcery spell each turn, copy that spell. You may choose new targets for the copy.

Worst Fears

You control target player during that player's next turn. Exile Worst Fears. (You see all cards that player could see and make all decisions for the player.)

Awaken the Blood Avatar

As an additional cost to cast this spell, you may sacrifice any number of creatures. This spell costs {2} less to cast for each creature sacrificed this way.
Each opponent sacrifices a creature of their choice. Create a 3/6 black and red Avatar creature token with haste and "Whenever this creature attacks, it deals 3 damage to each opponent."

Extus, Oriq Overlord

Double strike
Magecraft — Whenever you cast or copy an instant or sorcery spell, return target nonlegendary creature card from your graveyard to your hand.

Extus, Oriq Overlord // Awaken the Blood Avatar

Firesong and Sunspeaker

Red instant and sorcery spells you control have lifelink.
Whenever a white instant or sorcery spell causes you to gain life, Firesong and Sunspeaker deals 3 damage to target creature or player.

Pestilent Spirit

Menace, deathtouch
Instant and sorcery spells you control have deathtouch. (Any amount of damage they deal to a creature is enough to destroy it.)