Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

End the Festivities

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

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Pyretic Ritual

Fork

Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy.

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Seething Song

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Mountain

Display of Power

This spell can't be copied.
Copy any number of target instant and/or sorcery spells. You may choose new targets for the copies.