Virus Beetle

When this creature enters, each opponent discards a card.

Burglar Rat

Duress

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

Pilfer

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

Elderfang Disciple

Vicious Rumors

Vicious Rumors deals 1 damage to each opponent. Each opponent discards a card, then mills a card. You gain 1 life.

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.

Let's Play a Game

Delirium — Choose one. If there are four or more card types among cards in your graveyard, choose one or more instead.
• Creatures your opponents control get -1/-1 until end of turn.
• Each opponent discards two cards.
• Each opponent loses 3 life and you gain 3 life.

Swamp

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.