BS-04 is the fourth boss from Raiden III.
BS-04 is a giant cone-shaped spaceship which uses a series of rocket boosters on it's body. The boss has three phases fought in sequence. It has guns all over it's body, most of which can be destroyed. Whenever a series of guns on a portion of it's body is destroyed, that portion is detached. Since the boss will be constantly sweeping the screen with bullets, it is recommended to destroy the guns to lower it's firepower.
|Raiden||Desert Spider - Flying Fox - Phalanx MK-III - Gijido - Land Crown - Guardian - Antonov Ma-27 - Doreineji Core|
|Raiden II/DX||Grand Crawler - Death Walkers - Albatross - Battle Axe - Thunder Fortress - Black Bird - Graphite - Huge Satellite - Mother Haven - Gray Nodule|
|Raiden III||BS-01 - BS-02 - BS-03 - BS-04 - BS-05 - BS-06 - BS-07|
|Raiden IV||Exerey Iss - Ordo, Fulas and Mairazard - Famel Ya - Aguen and Ewat - Da Rutura - Isdogaram - Horda Gardia - Horda Gestorada|
|Raiden V||Platon - Great Horn - Kraken - Spice Birds - Blow of Hornet - Messiah - Angel - Humpty Dumpty - Divine Rampart|