In my community 40
gal, SHerbert the betta is the beat cop on the take..he patrols constantly, breaks up fights, protects the domain of the BKG from pesty clowns and rummies..... but isn't above stealing or bluffing.
He is very interactive and a prescence in that tank....
He is bold but not bullying, unless you count snatch and grabs of prize ntidbits from the very Knife he usually protects from other fish....
It makes quite a little aqua drama.
then on the whole other side of the scale:
there is my colisa Dragon..who killed all his first tankmates except the ones I saved just in time.... two females. I had bought 7 gourami. Mostly female. HE tolerates the mean botia in his tank.
And the gorgeously perfect female plakat that has killed 5 other betta and some otos, cories, snails, shrimp and her own reflection if she could. plus the many fish she killed in her former home (including one sister, two young oscars, a jewel, a ton of catfish and rams and tetras and others I can't recall except her total was 26 in one week before she was to be executed by large oscar)
see? IFFY I love Sherbert in the one tank..I wish bettas could go in ALL my tanks over 10.