If I use Power Siphon and my oppenent uses Thunderbolts on his Avengers to be a Mystic . Can I use Power Siphon to steal Avengers and become a Mystic myself?

what no one know the answer to this

You would be an Mystic. Thunderbolts changes the team ability your opponent's Avengers to whatever ability he chooses. With Siphon Power, you can copy that ability.

Patience, young grasshopper...

Is this a fact then.....Cause I'm getting other rulings from other people

Here's an answer from the FAQ that might help.

Q: Can a wild card copy the team ability that a character with Siphon Power has chosen?
A: No. In order for a wild card to copy a team ability, the character the team ability is being copied from must possess that team ability. Since other wildcards (including the one using Siphon Power) do not actually possess the team ability that they are using, the team ability cannot be copied by a different wild card.

Notice that Siphon Power users can't copy a TA that a Wildcard has borrowed. This is because the Wildcard doesn't actually posses a copiable TA; it posses its Wildcard TA that lets it use other TA temporarily.

Meanwhile, Thunderbolts actually changes the Avengers TA description to whatever new TA the T-Bolter wants. So, the T-bolted character does posses the new TA; their old TA has been completely rewritten. Since they posses the new TA, Siphon Power can copy it from T-bolts, unlike when Wildcards simply use another TA temporarily.

Actually contacted Hair10 about this. And He said you can't . Cause you can't use your oppenents cards

Hmm...

Yeah, I forgot about that little part. (for some reason, I guess I was thinking it only applied to Mind Control)

Well, if Karl says its so, then it is so. No argument from me.

no way normalview was wrong about heroclix rules. I would have never thought that possible...

It happens pretty frequently, actually. Usually when I try to recite something from memory. That's why I check the documentation before almost every post... 'cause that time or two I don't verify something, that's the time I am recalling it incorrectly.