im pretty sure it means no characters, friendly or opposing can heal.
i just wanted to be sure.

"Other characters" means all other characters.
"Other friendly characters" means other characters on your force.
"Opposing characters" means only opposing characters.

I am not aware of how Thanos' power is worded, but I think that covers all possibilities.

You are correct:

AVATAR OF DEATH: Other characters can't be healed.

No other characters can be healed, friendly or opposing.

Note that "healing" means "Healing", not just anything that turns the dial towards the beginning. Xavin's trait lets his dial be reset back to the first click under some circumstances, but doesn't call this "healing", so Thanos' trait won't prevent it.

thanks guy, very helpful!

A follow up question to this. What if you're opponent is also running Thanos? Would this prevent either Thanos from healing or do they ignore each other's trait?

They both would not be able to heal. There is no wording about them being able to ignore anything.

Hmm. I'm inclined to side with you. Any chance an orange could give us a ruling? Make it official and all that?

He's right. There's really no conflict:
Thanos A's trait means that characters other than Thanos A can't be healed.
Thanos B's trait means that characters other than Thanos B can't be healed.
Thanos A is not Thanos B, so he can't be healed.
Thanos B is not Thanos A, so he can't be healed.
Everyone else is neither Thanos A nor Thanos B, so they definitely can't be healed.

Now, if the trait read "Only Thanos can be healed", there'd be some issues, but it doesn't, so there aren't.

Thank you red king and dontcare. It makes sense that no one heals.

No, it's been consistently ruled that the use of a character's name in game text refers only to that specific instance of the character. That text would still leave both Thanosi unable to heal.

What you want is, "Only characters named Thanos can be healed.".

Right. That's what would create the problem. If the trait read, "Only Thanos can be healed," you end up with this situation:
Thanos A has a trait that says only Thanos A can be healed.
Thanos B has a trait that says only Thanos B can be healed.

So Thanos A tries to heal. He says only he can be healed, but the other guys says only the other guy can be healed. So who's right? Probably, it would be ruled that (implied0 can't trumps can, so neither could heal, but the point is, it's not as cut-and-dry as the actual wording.

"Only characters named Thanos can be healed" would also be problem-free. Both heal. And that SV Thanos over there heals too.