Necromancer's Familiar

Flying
Hellbent — This creature has lifelink as long as you have no cards in hand.
{B}, Discard a card: This creature gains indestructible until end of turn. Tap it.

Tragic Fall

Target creature gets -3/-3 until end of turn.
Hellbent — That creature gets -13/-13 until end of turn instead if you have no cards in hand.

Anthem of Rakdos

Whenever a creature you control attacks, it gets +2/+0 until end of turn and this enchantment deals 1 damage to you.
Hellbent — As long as you have no cards in hand, if a source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Rakdos Pit Dragon

{R}{R}: This creature gains flying until end of turn.
{R}: This creature gets +1/+0 until end of turn.
Hellbent — This creature has double strike as long as you have no cards in hand.

Bladeback Sliver

Hellbent — As long as you have no cards in hand, Sliver creatures you control have "{T}: This creature deals 1 damage to target player or planeswalker."

Taste for Mayhem

Enchant creature
Enchanted creature gets +2/+0.
Hellbent — Enchanted creature gets an additional +2/+0 as long as you have no cards in hand.

Slaughterhouse Bouncer

Hellbent — When this creature dies, if you have no cards in hand, target creature gets -3/-3 until end of turn.

Sea Gate Wreckage

{T}: Add {C}. ({C} represents colorless mana.)
{2}{C}, {T}: Draw a card. Activate only if you have no cards in hand.

Hollowborn Barghest

At the beginning of your upkeep, if you have no cards in hand, each opponent loses 2 life.
At the beginning of each opponent's upkeep, if that player has no cards in hand, they lose 2 life.

Neheb, the Worthy

First strike
Other Minotaurs you control have first strike.
As long as you have one or fewer cards in hand, Minotaurs you control get +2/+0.
Whenever Neheb deals combat damage to a player, each player discards a card.

Skophos Reaver

During your turn, this creature gets +2/+0.
Madness {1}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Gobhobbler Rats

Hellbent — As long as you have no cards in hand, this creature gets +1/+0 and has "{B}: Regenerate this creature." (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Demon's Jester

Flying
Hellbent — This creature gets +2/+1 as long as you have no cards in hand.

Bloodhall Priest

Whenever this creature enters or attacks, if you have no cards in hand, this creature deals 2 damage to any target.
Madness {1}{B}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Gibbering Descent

At the beginning of each player's upkeep, that player loses 1 life and discards a card.
Hellbent — Skip your upkeep step if you have no cards in hand.
Madness {2}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Demonfire

Demonfire deals X damage to any target. If a creature dealt damage this way would die this turn, exile it instead.
Hellbent — If you have no cards in hand, this spell can't be countered and the damage can't be prevented.

Cutthroat il-Dal

Hellbent — This creature has shadow as long as you have no cards in hand. (It can block or be blocked by only creatures with shadow.)

Cackling Flames

Cackling Flames deals 3 damage to any target.
Hellbent — Cackling Flames deals 5 damage instead if you have no cards in hand.

Gathan Raiders

Hellbent — This creature gets +2/+2 as long as you have no cards in hand.
Morph—Discard a card. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Jagged Poppet

Whenever this creature is dealt damage, discard that many cards.
Hellbent — Whenever this creature deals combat damage to a player, if you have no cards in hand, that player discards cards equal to the damage.

Slithering Shade

Defender (This creature can't attack.)
{B}: This creature gets +1/+1 until end of turn.
Hellbent — This creature can attack as though it didn't have defender as long as you have no cards in hand.

Headless Specter

Flying
Hellbent — Whenever this creature deals combat damage to a player, if you have no cards in hand, that player discards a card at random.

Blood Scrivener

If you would draw a card while you have no cards in hand, instead you draw two cards and you lose 1 life.

Nihilistic Glee

{2}{B}, Discard a card: Target opponent loses 1 life and you gain 1 life.
Hellbent — {1}, Pay 2 life: Draw a card. Activate only if you have no cards in hand.

Keldon Megaliths

This land enters tapped.
{T}: Add {R}.
Hellbent — {1}{R}, {T}: This land deals 1 damage to any target. Activate only if you have no cards in hand.

Fool's Tome

{2}, {T}: Draw a card. Activate only if you have no cards in hand.

Terminal Agony

Destroy target creature.
Madness {B}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Infernal Tutor

Reveal a card from your hand. Search your library for a card with the same name as that card, reveal it, put it into your hand, then shuffle.
Hellbent — If you have no cards in hand, instead search your library for a card, put it into your hand, then shuffle.

Twinstrike

Twinstrike deals 2 damage to each of two target creatures.
Hellbent — Destroy those creatures instead if you have no cards in hand.

Brink of Madness

At the beginning of your upkeep, if you have no cards in hand, sacrifice this enchantment and target opponent discards their hand.

Ragamuffyn

Hellbent — {T}, Sacrifice a creature or land: Draw a card. Activate only if you have no cards in hand.