We need to deal with Zombraluz before more soldiers reach us. Both escaping and capturing him will require dealing with his gun.
In order to deal with his gun, we need to use all the advantages we have over him: danmaku, demonfire, flying, being small, mobility not involving legs; Kasen - danmaku, equal at martial arts, second combatant; Yumemi - brainy, arrogant, location (she was left back some hallways, right?), radio.
please add any I've forgotten.