Post two Аниме characters from different animes that would probably hate each other to hell and back if they met.

Наруто (from Naruto) and Zeref (from Fairy Tail). Zeref is the meaning of evil and will stay evil so Наруто can't talk him out of it and stuff... hate in Наруто is unlikely but possible.

Alice Baskerville MEATS Italy
*see what I did there*

Vash (Trigun) would hate Kenpachi Zuraki (Bleach) since he is all about killing and violence

Perhaps Levi (Shingeki no Kyojin) and Harley (Pokemon).