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.)

Pyretic Ritual

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Endbringer's Revel

{4}: Return target creature card from a graveyard to its owner's hand. Any player may activate this ability but only as a sorcery.

Isochron Scepter

Imprint — When this artifact enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Dark Ritual

Spellbinder

Imprint — When this Equipment enters, you may exile an instant card from your hand.
Whenever equipped creature deals combat damage to a player, you may copy the exiled card. If you do, you may cast the copy without paying its mana cost.
Equip {4}