Pilfer

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

Fake Your Own Death

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control and you create a Treasure token." (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Tinybones, Bauble Burglar

Whenever an opponent discards a card, exile it from their graveyard with a stash counter on it.
During your turn, you may play cards you don't own with stash counters on them from exile, and mana of any type can be spent to cast those spells.
{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

Go for the Throat

Thought-Stalker Warlock

Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, choose target opponent. If they lost life this turn, they reveal their hand, you choose a nonland card from it, and they discard that card. Otherwise, they discard a card.

Bandit's Talent

(Gain the next level as a sorcery to add its ability.)
When this Class enters, each opponent discards two cards unless they discard a nonland card.
{B}: Level 2
At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, they lose 2 life.
{3}{B}: Level 3
At the beginning of your draw step, draw an additional card for each opponent who has one or fewer cards in hand.

Swamp

Binding Negotiation

Target opponent reveals their hand. You may choose a nonland card from it. If you do, they discard it. Otherwise, you may put a face-up exiled card they own into their graveyard.

Burglar Rat

When this creature enters, each opponent discards a card.

Withering Torment

Destroy target creature or enchantment. You lose 2 life.

Cerebral Confiscation

Choose one —
• Target opponent discards two cards.
• Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.