Ok for all of you that need to know how to beat the final boss, here we go.
Weapons: Short Shield, Lightning,
Slow Time.
All you have to do is use the slow time as soon as you can. Get on top of him and use all of your lightning and your short shield. That should beat him. The thing is that you HAVE to do this as fast as possible so you don't loose all you life and explode.
Keep this going.
onimaru freakin rocks your faces! Best mele guy in the game dude. him plus cain solomon and that archer chick is ownage. all you have to do with onimaru is on your first turn, use his sword flury (so you don't waste a double slash if they change cards) next turn use double slash. if they are below 25% health, they're gonna change cards. So, we intercept. this is like all you have to do on these fools.
 "CycloManiacs"){kind=icon}
 "Crunchball 3000"){kind=icon}
 "Punk-o-matic"){kind=icon}
 "UPGRADE COMPLETE!"){kind=icon}
 "Little Wheel"){kind=icon}
 "Hedgehog Launch"){kind=icon}
 "Heavy Weapons"){kind=icon}
 "the i am bored so i chat game"){kind=icon}
 "Treasure of Cutlass Reef"){kind=icon}
 "Learn to Fly"){kind=icon}
 "Free Rider 2"){kind=icon}
 "Post it Draw it"){kind=icon}
 "Kongai"){kind=icon}
 "Pirate Defense"){kind=icon}
 "Crush the Castle"){kind=icon}
 "Music Catch 2"){kind=icon}