Confederate B7 Sith droid

on gustafar in 22bby after the sith lord darth vader exucuted the separatist council the neimodien rear adrimal  Garlen Mastigar contracted the geonesiens on gustafar the planet that mastigar was blockading asked the  engineers to create the most powerful battle droid ever.using b1 battle droid parts the engineers reconstructed the with lightsabers using byber crystals to substute for lightsaber crystals the droids fought as marines on boarding ships during the navy battle above gustafar they fought against the new empire on the suface to during the ground battle on gustafar killing hundreds of clones however they were deactivated at the ed of the battle with this defeat forced mastigar to go into hiding again.