Size will be fine. Either get a that will house him nicely to isolate him from the others intill you find away to sort it.
Im thinking maybe getting another 4 Angels to make a group that might sort him out but not sure with the other fish in the tank it might be over stocked.
Personally if it was me id consider just having the one Angel and giving the bully to a friend who is Angeless but has a tank the right size for him.
ive got a net
My tank is 4 foot 45 gallons! Ive got a small net!
Have you got a net, or a container it can fit in to float in the tank, so you can isolate it?
Should i just put it in a bucket with some warm water??
No as the water in the bucket can soon lose temperture. Is there any other LFS around you that may take him off your hands?
We have a few round us that will take them in for 2 reason.
1. To make sure the fish are safe and sound
2. Profit on a resale of the fish