Cabal Ritual

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

Simian Spirit Guide

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

Striped Riverwinder

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Cycling {U} ({U}, Discard this card: Draw a card.)

Crumble

Destroy target artifact. It can't be regenerated. That artifact's controller gains life equal to its mana value.

Khalni Garden

Khalni Garden enters tapped.
When Khalni Garden enters, create a 0/1 green Plant creature token.
{T}: Add {G}.

Manamorphose

Add two mana in any combination of colors.
Draw a card.

Aisling Leprechaun

Whenever Aisling Leprechaun blocks or becomes blocked by a creature, that creature becomes green. (This effect lasts indefinitely.)

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Ingot Chewer

When Ingot Chewer enters, destroy target artifact.
Evoke {R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Mountain

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dregscape Zombie

Unearth {B} ({B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Swamp

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Fyndhorn Brownie

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Rite of Flame

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.

Dark Ritual

Font of Fortunes

{1}{U}, Sacrifice Font of Fortunes: Draw two cards.

Dangerous Wager

Ulamog's Crusher

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)
Ulamog's Crusher attacks each combat if able.

Dragon Breath

Enchant creature
Enchanted creature has haste.
{R}: Enchanted creature gets +1/+0 until end of turn.
When a creature with mana value 6 or greater enters, you may return Dragon Breath from your graveyard to the battlefield attached to that creature.

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.)