The Joker would not invited.
His butler, Alfred Pennyworth, would be invited.
Joker
He would know all the same people he knew before he got married.
He is a fictional character and this is not possible.
cat women, penguin, joker, bane
Any one of the rogue gallery would not get an invitation, but if you were to choose, highest on that list would be the Joker.
The Marvel superheros and the villains.
his sidekick
Most people would not get an invention. Inventions are few and far between even among fictional super heroes.
It is not expected but it would be nice to do so.
you and any norrmal citizon also anyone he is an enemy of
Batman would beat Sonic.