Ive thought about a gw specific character, but instead of an event. Just scale gw down alittle in difficulty. Then adda hard mode difficulty that is Gw scaled up some.
For the end rewards of hard mode switxh the 12th node box color to red instead of purple and add a seperate red gw currency 400 at the last node. That can be spent on the new character. And make thst character Bossk. Also they could add a really low droo of a zeta on the 12th node, kind of like gw can give an omega