f25a08f0_Secrets_for_PSP___GameRankings__Unlockable
[How to Unlock] Spark Mandrill [Unlockable] 
After the miniboss you will run into Vile's armor, grab it, ride it until the end of the floor and then jump out. (You can also use the boomerang)
Mega Man Maverick Hunter X Cheats, Codes, and Secrets for PSP - GameRankings