Kingdom Hearts II Mickey and killing bosses

Why is Mickey in KH2 unable to kill any of the bosses?
In CoM, he is capable of killing the bosses in R/R if you make a use of his Card or MM Miracle the final blow. In KH2 that does not happen.

What in-universe explanation can justify this? "In-universe" as in within the bounds of the KH universe. No BS like "because SE/DiZney said so".

I doubt it has to do with the alignment of his Keyblade, given that Heartless are hearts corrupted by Darkness and he can slay the lower ranks of them perfectly well, so it is possible to combat Darkness with Darkness. So what is it?

Remember, in-universe explanations only. No breaking the Fourth Wall.

 

All bosses require a finishing combo move to kill. Mickey has no such thing. Therefore, unable to kill bosses. He's just there so Sora can regenerate.

 

what he said but Mickey can kill one boss.... but only using cheats on AR Max

 

Yeh most bosses need a finishing combo to destroy them.

 

What boss is that then evil man?

 

just as saurai said.....try and look on youtube....mickey's fight with axel.....no combo...he died....

 

Luxford, but u need a cheat to play as Mickey. after u get turned into a dice, ur Normal Command Menu is unlocked and u can just use a Limit Attack to kill him

 

That about sums it up for ya, u need a finishing combo to beat a boss and mickey has no such maneuver so...there, that seems simple enough

 

yup you need the whole "finishing combo" thing at the end xD i always die like that cuz i can't get it right, especially when i killed sephiroth (i freaked out) xP

 

yeah, you will definitely freak if you almost beat sephiroth without a combo...it's sucks it's a good thing i survived from my guard ability.....let's see..my hp was ensured for 1 hp....my mp recharging....and it's good thing i stunned him with the counterattack or i would die in an instant....

 

So... The popular opinion seems to be that Mickey was stupid enough to forget to learn a Finishing Move and thus cannot kill a KH2 boss, whereas the CoM bosses are that much weaker that he can still kill them regardless?