Who Was That Masked Man?!

At least they're doing this one thing that's keeping me interested in following the show. Here's what I posted in an earlier thread, along with some updates:

When that mystery character made his second appearance, there was one moment that might be a clue to who he is. They were on another planet, and Ben told him to come along with him on whatever mission they were doing. At that moment he clenched his fist and said "Yes!" to himself like a young fanboy celebrating that he gets to go with his hero. That suggested some possibilties as to who it was:

1. Jimmy - the fanboy who runs the website about Ben. But how did he get all those skills and powers?

-- Jimmy was ruled out in a recent weekday morning episode. We also learned that the mystery character calls himself Spanner.

2. A younger Ben - It's another one of those time travel things where young Ben meets the older one. But why would he hide himself (and not use his Omnitrix)?

3. Ben's son - Another time travel thing, like with Ben 10K, except it's Ben's son from the future going back to be with his dad when he was young. I wonder if his mother is Julie (a character we haven't seen yet in Omniverse).

-- A recent episode showed Ben visiting Ben 10K in the future. At one point Ben 10K is talking over a video linkup to "Kenny," who would seem to be his son. So far this seems the strongest possibility. And the name fits: Ken 10!

4. Or maybe Ben's daughter. Jennifer? Jen 10!