This is why people don't play Absurdly Extra in BPoHC
6Watch as a young scientist luckshits her way past undodgeable barrages of bullshit. Honestly just don't play this mode. It's not worth it. Also keep in mind white bullets are the strongest enemy bullet type.
So you may have realized that I'm using Suzumi's bomb and flashbomb but I'm playing as Tsubakura. How is that? Well it's simple really. All I had to do was beat every route to fight every final boss, which means both Haze Castle and Pagoda route, plus the 3 returning bosses, also going through with a different team to fight Yabu, Tsuba, and Shion as final bosses as well. Then I had to play through once more staying on shrine road to fight Suzumi as a final boss to unlock extra. Now do Suzumi's route with each team to get all of them in extra, then beat the 3 extras to unlock Extra+Alpha then beat extra+alpha with each shot to unlock Suzumi as a playable character, then do 1 last playthrough with Suzumi to fight another Suzumi from an alternate point in history to unlock extra with her then do extra+alpha with her and finally the team restrictions will be removed and you can use whoever you want. Keep in mind 1 playthrough of the story mode takes around 50 or so mins. So that's 13 main game playthroughs and about 7 or 8 extra playthroughs all to get team restrictions removed. Also you have to beat unreal at least once to get Absurdly Extra, which Unreal with upgrades is piss easy unless you go Pagoda route so yeah.