After many bettas, I agree, you have to move the Betta! I just had to move a Betta out of a community tank last night... I got some new plants and rearranged things. Next thing I know he is going after everyone... I threw together a back up Betta tank and had him out within the hour. Waiting until morning would gave meant more shredded fins and possibly death. In my experience, once they decide to be a jerk, there is no going back! I do tend to try them in a different community tank after a bit of time out. When they are the new guy or girl they tend to be on their best behavior again. But definitely watch them closely.