HISTORY:during his time as a member of the red pirates with captain marvelous and akared, basco got his hand on all the keys used for the sixth and extra senshi. he betrayed the other two and joins the zangyack, having a partnership with damaras(who would sometimes give them gormin). he confronted marvelous in episode 15, he summoned timefire, dragonranger, shurikenger, dekabreak, and kingranger to fight the gokaiger, only for them to use there final wave finishers to revert them back into keys. basco then unleashed the other ten 6th senshi: magishine, go-on gold, go-on silver, kiba ranger, boukensilver, shinken gold, gosei knight, gao silver, abarekiller, and mega silver. they kidnap the four gokaiger, only for marvelous to cheat in there deal, and free the other four. basco summons the 10 senshi to fight, only for the gokaiger to get the keys, which they use the next episode. at the end of the episode, basco reveals to have 10 more keys: female shinken red, deka master, deka swan, wolzard fire, magi mother, signal man, zuuban, rio, mele, and bull black. in episode 20, the gokaiger get the bull black, and in episode 31, they manage to get back the rest.
in GOKAIGER GOSIEGER 199, black cross fuehrer manages to steal all the ranger keys and build a device that can summon all of them(as supposed to basco's trumpet; the rapparatta, which can only summon five at a time) at once. the gokaiger, assisted by the goseiger and gosei knight, split up and fight them(EX. they first take out the sentai teams that used giant cannons and gosei knight fights the 6th senshi) they defeat them easily(most likely since the device used to summon them couldnt handle over 150 summons as supposed to the rapparatta sumoning five at a time and never went past 15 at a time) back cross fuehrer was defeated by goren gokai-OH.