Any knowledge is knowledge to me
I am aware of New Sun (Gambit) and that not only he defeated Phoenix of his reality, but he was capable of traveling to other universes and affecting them.
Bete Noir I believe was meant to be the opposite of the Phoenix Force (like Goblin Force was), however, the new writers aren't too keen on incorporating Bete Noir or Goblin Force. I can understand why. Neither were written as well as they could have been. I'm for giving those second chances ^_^
As for New Sun, he's been used a lot in debates of what would or should count as multiversal as a whole, or multiversal in feats. So... good mention