Hey so, in LoL canon, Evelynn was the one who murdered Vayne's family. Do you think that during Ahri's 5 year vacation where Evelynn was getting accused of murder left and right, she could have been accused of killing Vayne's parents and Vayne had sworn some sort of revenge similar to LoL? Maybe she could be spreading rumors to damage Evelynn's career and destroy her life, or she could discover Eve is a succubus and try to go all Van Hellsing on her ass like in LoL.
You know...I'm sticking with "missing male celebs" K/DA canon. LOL canon is it's own thing (hence why I do LOL persona and K/DA persona). I try not to copy and paste LOL canon with the K/DA universe. There can be an "alternate" or edited verson of LOL canon, which you suggested, but I particularly don't like this tidbit. And I have no idea who Vayne is ( y'all better not give me a paragraph, describing who Vayne is bc 1) I won't read it so don't waste your time, 2) I will forget anyways, 3) I refuse to learn bc I'm stubbornly gay for only K/DA)