Reaper King (EDH / Commander)

Strategy: assemble 3 "champions" (so-called because of the "champion a creature" ability) and/or clones that can become champions. These will create an infinite loop of exiling each other in turn. If at least one of the creatures is a scarecrow ([[Changeling Berserker]], [[Changeling Hero]], or [[Changeling Titan]]) and [[Reaper King]] is in play, this destroys all the opponents' permanents. Pretty neat. Also, the loop can be broken by destroying [[Reaper King]] itself, so there is no need to destroy your own stuff.

[[Maskwood Nexus]] and [[Arcane Adaptation]] can allow the combo to work with other champions that aren't normally scarecrows.

[[Corpse Knight]] (chosen over other similar effects for its tutorability, see below) and [[Outpost Siege]] on Dragons can substitute in for [[Reaper King]] to just kill everyone instead. [[Outpost Siege]] can be safely set to Khans too (and it probably usually is unless the rest of the combo is already set up) because it's not critical.

If [[Nikara, Lair Scavenger]] is on the battlefield and [[Yannik, Scavenging Sentinel]] is one of the champions, that will lead to a build-your-own [[Yawgmoth's Bargain]]. Having [[Nikara, Lair Scavenger]] in play won't result in suicide because [[Yannik, Scavenging Sentinel]]'s ability that puts +1/+1 counters on creatures can target 0 creatures.

In the meantime, some of the champions can be used as removal to stay alive, and the clones can be used to copy whatever cool stuff is around.

[[Sakashima of a Thousand Faces]] and [[Mirror Box]] allow the clones to copy [[Reaper King]], which is pretty cool.

[[Liliana's Contract]] is a card draw spell, but setting all creatures to Demons can result in a random win.

[[Deathbellow War Cry]] is sweet because even without changing any creature types, it can tutor all three natural changeling champions for an instant combo (assuming the finisher piece is in play). Setting all creatures to Minotaurs can also allow [[Corpse Knight]] to be found as the fourth Minotaur, which forms the complete combo.

[[Defense of the Heart]] can get any 2 combo pieces, including [[Corpse Knight]] if necessary.

[[The World Tree]] can also tutor the natural changeling champions for an immediate win.

[[Moritte of the Frost]] is a clone that is tutorable with both [[Deathbellow War Cry]] and [[The World Tree]], so it acts as a replacement in case one of the three natural changeling champions is in the wrong zone or otherwise inaccessible.

The protection spells are there to allow [[Reaper King]] to be played earlier on and sit on the battlefield, which allows the combo pieces to be played more slowly.

[[Guided Passage]] is sweet because it guarantees a land drop, it can be used politically to get a card the table needs, and it is almost guaranteed to get a sneaky combo piece in the meantime because the only non-combo creature in the deck is [[Druid of Purification]].

Always remember: It's harvest time.