Krovikan Vampire

A combat-damage theft engine, and one of the earliest cards to treat dying-in-battle as a resource rather than an event. The mechanism is precise about its trigger: a creature has to take damage from this Vampire and die that same turn, but it does not have to die directly to that damage. A creature you bloody in combat and then finish off with a second source, or that gets sacrificed later in the turn, still returns at the end step, because the card asks only that it was dealt damage and that it died, not how. The steal also resolves at the end step rather than on death, which gives the effect a window other players can interact with. What it grabs, it grabs conditionally; the leash clause ties every stolen body to the Vampire's survival, sacrificing the lot the moment you stop controlling it. That makes the card a tempo lever wearing the costume of permanent advantage: you are renting creatures off the back of a 3/3 that has to keep living to hold the lease. The design predates the modern templating of "exile until" and "gain control for as long as," and it shows in the bookkeeping it asks for; theft here is expressed through death triggers and a sacrifice trigger rather than a stated duration. Building a steal effect onto combat math, and onto a body that can be removed to undo the whole haul, is the wrinkle that makes Krovikan Vampire read as a fragile aristocrat rather than a value rock.