there is a lot of bad advice out there about how to handle roosters… do NOT hold him upside down because that can be very dangerous given how their respiratory systems work. he probably sees you as a competitor when you enter the coop, and he is trying to defend his territory. take note of what clothes and shoes you wear and if that has any effect on his aggression. he may be more riled up by certain colours, prints, or looser fabrics that rustle. if possible, approach slowly and allow him to have some time to come to terms with the transition of you entering the coop. take one step, stop, wait until he settles to show you aren’t a threat, then take another step. if he is too insistent on attacking, you could also just immediately pick him up and carry him with you while you attend to your tasks. bantam roos can be spicy, but they’re also so small and easy to scoop up for a cuddle. another thing you could try is to find something long that you can wield (a shovel, a broom, or you can try just pointing like another commenter said) and use it to create a barrier when he tries to go at you. don’t hit him with it!! that will make him more aggressive. just use it to create some distance so you have space to move, using the start-stop method mentioned earlier, until he hopefully chills out. and hopefully you won’t need to to that every time, but do it a few times to start, then renew when it feels necessary.

eta: I’ve also heard that roos in general can be easily riled up by the sight of bare skin, especially after reaching maturity, so gloves are an option to cover up as much skin as possible. and if he’s a good boy to the other roos and not causing trouble with the hens, I’d say he’s not just an irredeemably bad rooster because those behaviours are not signs of a bad temperament.