Kakusei Sol uses a red awakening power coupled with a permanent Dragon Install-like effect, infinite Tension and impressive Fire techniques. Defeating Kakusei Sol and Kakusei Ky on the last stage of GG Boost mode unlocks Zako 1, 2, and 3.
In order to unlock him, the player must first have Sol's EX version unlocked by beating Arcade Mode. Playing GG Boost or Scramble as Robo-Ky II in RKII Factory Mode on at least Normal difficulty, one must defeat Kakusei Sol and Kakusei Ky in Stage 5-E (Last Dance) with 1,400,000 points or more and not have used any warp points. One must then choose not to return to the factory and a giant Robo-Ky II ("Robo-Ky II Substance") will appear. Defeating it unlocks Kakusei Sol and Ky.
To select him, the player must simply highlight Sol Badguy on the Character Select Screen and press Start twice.
Compared to normal Sol, he mostly mirrors most of EX Sol's moveset. He also has 1 new exclusive technique known as Dragoon Revolver (a midair Bandit Bringer-esque punch that shoots a fireball diagonally to the ground and makes it emit a row of massive DI-enhanced-Gun Flame bursts), and his Savage Fang is called Savage Flame instead (albeit with the same animation as with EX Sol's move).