User blog comment:Emptylord/2017 Patch Notes (Unofficial)/@comment-3391671-20170701200609/@comment-3974211-20170702195921

Regarding, while it wasn't my original intent to have him be corrupted - the more I fantasise Darkin lore, the more I want it so. Assuming the direction of his lore is skill canon, Varus made a deal with the Darkin - and so perhaps Varus has agreed to surrender willingly, once his vengeance has been enacted (it would explain why the Bow doesn't seem to be actively seeking to dominate him, as with Rhaast and Aatrox).

Then, the parallels to the Horsemen of the Apocalypse means that The Darkin Bow is Pestilence/Conquest, the White Horseman - since he wields a bow (just like Death wields a Scythe and War wields a Sword). Conquest represents Dominance/Victory. It is a slow death. A slow corruption would make a delicious amount of sense, thematically.