Hi there and
to the forums!
It's wonderful, as others have said, that you were able to foster all the birds until they found good homes.
As for your little troublemaker, I agree that it sounds like he's being difficult just for the sake of being difficult and getting attention as a result. As Dee said, it probably doesn't help that he's nearing his "teenager" stage, which contributes to his crabbiness.
I would take it slowly and devote lots of time to him without being with the dragons. Perhaps moving him into a room where there are no other animals would help? Start at square one and get to know him. You'll have to go slow, because he'll still be bossy and petulant. Just try not to get frustrated, and if you feel like you are, just leave the room for a while. As you said, it doesn't help either of you to be so frustrated with each other
Other than that, I can't add much to the great advice already given. I hope things progress well and please do keep us posted on his progress!
If you have any questions after reading through anything, be sure to ask as we'd love to help.
Hope to see you and your many reptiles (and bird, of course
) around the forums!