Hidetsugu and Kairi
The fusion of two Kamigawa legends produces a card that spans the full arc of a threat's life: it refills your hand the moment it lands and detonates when it dies. The enters trigger is not raw card advantage so much as selection under a cost. Drawing three and returning two to the top nets one card while stacking your library, which is the tension the design wants you to resolve: whether to bury dead draws or seat a specific card on top, and whether that ordering serves you now or the death trigger later. That death trigger is where the two halves talk to each other. Exiling the top card and draining an opponent for its mana value rewards a top-heavy stack, and a well-placed spell can fire off for free once the body hits the yard. The enters ability is what lets you engineer that outcome: seat an expensive card on top with the draw, then send the 5/4 flier to the graveyard on your terms. The body is almost incidental to the machine, a clock that happens to be worth killing, which is precisely the point. Most creatures punish an opponent for leaving them alive; this one is built so that killing it fires the payoff, turning lethal removal into the trigger that pulls the second barrel.
