Mephisto vs The Watcher

vs

Mephisto tried to date The Watchers sister. or something..
The Watcher says "Ohh Noo. Shits on NOW you little Beeeyoutttchhh!"

Who wins?

In Normal space. In Mephs Realm.

Normal space : Watcher probably stomps
Mephisto's hell : Mephisto stomps

uatu