Skully first appears at the end of Dunewatch Castle on Planet Leisura, where he attacks the player inside a gunship different than the Gunship on Platinum Beach, where he warns the player about what would happen if the player messed with the Gold Bone Gang again, but then decides to attack the player right that moment, and begins the first battle, in this battle, Skully can shoot either green bullets or fireballs from his frontal cannon, he also can send out small robots that look similar to the defeated form for all of his ships. When he is defeated, part of the gunship will explode and destroy the gunship's decorations, Skully will than fly away inside what is left of his gunship.
Skully reapears at the end of Ragnablock Chasem on Planet Roohin inside a redecorated version of the same gunship. Where he tells the player not to enter Slitherstone Ruins because it's "under construction", but than atacks the player. In this battle, Skully will only fire green bullets instead of that and fireballs. He can also send out the small robots from the first battle and drop blocks on the player. When he is defeated, the decorations once again fall off of the gunship from an explosion on part of the gunship, and Skully will once more retreat with what's left of the gunship.
Skully makes a 3rd appearance at the end of the Bone Rattler on Planet Amyuzia inside a now much more decorated version of the gunship, where he tells the player that he was furious with his previous defeats, so he started redecorating his gunship (again) to battle the player once again on the Bone Rattler. In this battle, Skully can once more shoot both green bullets and fireballs, but are much harder to doge because the player can't move forward or backward in that stage, the small robots can also be difficult to doge for the same reason. When Skully is defeated, the decorations will once again be destroyed in an explosion, but this time Gold Bone will appear and order Skully to be put on deck swabbing duty as punishment for his defeat.
Skully's second to last appearance is in Amethyst Atoll on Planet Aquatis, where he destroys the Foe Finder 4000, and than attacks the player inside his new gunship. In this battle, Skully will still fire green bullets and fireballs, as well as send out the small robots from all of the previous battles, but this time Skully can also send out indestructible fishbones to charge at the player. When he is defeated, the gunship's decorations will once more be destroyed in a partial explosion, and Skully will once more fly away with what's left of the gunship.
Skully's final appearance is at the end of the GB-1 Space Dock on the Gold Bone Gang's base, where he tells the player that he was waiting for them the whole time in that area, and than says that his current gunship will be the gunship that defeated the player. In this battle, Skully still retains his original attacks, but this time he has a forcefield on the ship and can also go off screen and charge at the player with the gunship. When he is defeated, another partial explosion will occur, but this time it will disable the gunship instead of destroy it's decorations. Skully will than ask the player if they want to join the Gold Bone Gang, but the squad leader will automatically say no, another explosion will occur on the gunship shortly after, this time completely destroying the ship and Skully.