Whomst

Not a real word; made by the internet/ an internet slang. Came into usage after a meme, literally. Its supposed to be short of "who amongst (you/us)" Often used as joke in a conversation.

(Into a groupchat)
J : Whomst hath summoned the almighty one?
K : we tagged you, you idiot:|
J : Sighh speak peasant-!