The Theorist, Jace Beleren

Lifelink At the beginning of your end step, if you gained life this turn, surveil 1. If you put a card with mana value less than or equal to the amount of life you gained this turn into your graveyard this way, put that card into your hand.

At the beginning of each opponent's draw step, you draw a card. +1: Create a 1/1 blue Illusion creature token. −2: For each opponent, return up to one target artifact or creature that player controls to its owner's hand. −6: Draw three cards. Then put X +1/+1 counters on each creature you control, where X is the number of cards in your hand.

At the beginning of each end step, if three or more creatures died this turn, this creature becomes prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)

Haste When this creature enters, creatures you control gain trample and get +X/+0 until end of turn, where X is the number of artifacts you control.

Haste When this creature enters, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

At the beginning of your upkeep, if this creature isn't prepared, it becomes prepared. 2: Put target card from your graveyard on the bottom of your library.

This creature enters prepared. Whenever you scry or surveil, creatures you control get +1/+0 until end of turn. This ability triggers only once each turn.

At the beginning of your upkeep, if this creature isn't prepared, it becomes prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)