Gamble

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

Lotus Petal

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

Final Fortune

Take an extra turn after this one. At the beginning of that turn's end step, you lose the game.

Cabal Ritual

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

Last Chance

Rite of Flame

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

Stunning Reversal

The next time you would lose the game this turn, instead draw seven cards and your life total becomes 1.
Exile Stunning Reversal.

Death's Shadow

Death's Shadow gets -X/-X, where X is your life total.

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.)