I will agree with RHX and kramsa.
Buy a nice little nano cube and they'll soon be impressed and want one, instead of fighting the fishes.
If you must fight the fish, i'd buy a male plakat..they are generally much more muscular than the domesticated betta (with long flowing fins) and are somewhat more aggressive...however, you wouldnt fight two dogs, so why fight two fish? If you want to see them flare, put a mirror next to his tank, or feed him tadpoles..
Currently keeping many wild betta species and other anabantoids.
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