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 your library.
Hellbent — If you have no cards in hand, instead search your library for a card, put it into your hand, then shuffle your library.

Demon’s Jester

Flying
Hellbent — Demon’s Jester gets +2/+1 as long as you have no cards in hand.

Cackling Flames

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

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.

Gobhobbler Rats

Hellbent — As long as you have no cards in hand, Gobhobbler Rats gets +1/+0 and has “: Regenerate Gobhobbler Rats.”

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.

Slaughterhouse Bouncer

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

Rakdos Pit Dragon

: Rakdos Pit Dragon gains flying until end of turn.
: Rakdos Pit Dragon gets +1/+0 until end of turn.
Hellbent — Rakdos Pit Dragon has double strike as long as you have no cards in hand.

Jagged Poppet

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

Anthem of Rakdos

Whenever a creature you control attacks, it gets +2/+0 until end of turn and Anthem of Rakdos 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.

Lyzolda, the Blood Witch Avatar

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.
Hellbent — At the beginning of your end step, if you have no cards in hand, each of your opponents discards a card.