#4 Facing Rey Mysterio
This would be another obvious but interesting direction to go in. Of course, it's a longshot to think that this would happen so soon, especially with how green Dominick presumably is in the ring.
However, wouldn't it be incredible if Rey Mysterio passed the torch over to his son? Apart from Andrade or Ricochet, there's no better superstar he could do that to and if you were to ask him, he would prefer to give the rub to his son.
Since Andrade vs Rey Mysterio has been done and dusted quite a few times, that is not likely to be the direction for his last stand. However, one thing we must admit is that it is a little odd how WWE is presenting Mysterio as the veteran who is far past his prime. While that is true only to some extent, he isn't exactly close to being done from a physical standpoint.
Mysterio still has quite a few years left in him as a performer and if that is the case, Dominick could be built up to eventually feud with him and perhaps even unmask him.