Gitaxian Probe

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

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

T: Add C. 1, T, Sacrifice this land: Destroy target nonbasic land. Activate only if an opponent controls four or more lands.

(B/P can be paid with either B or 2 life.) Target creature gets -5/-5 until end of turn.

Destroy target artifact. Flashback G (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.) When this creature enters, destroy target artifact, enchantment, or land.

Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard. Flashback 6B (You may cast this card from your graveyard for its flashback cost. Then exile it.)