Changeling Hero

Champion asks you to pay an existing creature into a new one, and the trade conceals an upside on every Champion card: the exiled creature is only gone while the Champion stands, returning fresh when the Champion dies. That means whatever you tucked away gets to re-enter the battlefield later, firing its arrival trigger a second time. Pair the Champion sacrifice with a creature whose entry effect you want to reuse and the five mana stops reading as a tempo loss and starts reading as a deferred value engine. The flexibility here comes from the keyword stapled to it. Its oracle text says "champion a creature," with no type restriction, so it can tuck away and recur anything; the Changeling line then handles the other end, because counting as all creature types simultaneously means any type-restricted Champion can in turn champion this one. Most Champion cards demand a specific creature type on one side or the other, which locks them into narrow chains. This one slots into a recursion loop from either direction, regardless of what is being recurred. The 4/4 lifelink body is the floor while that engine assembles, a clock that pads your life total against the aggression slower loop strategies tend to invite. It functions as connective tissue rather than a closer: a universal joint in a creature-recursion chain that does not care what passes through it.