Alternate final boss to NSMBU (What I'm hoping for, but isn't a reality... I think... IDK, I never saw what the final boss fight was

)
If a title for this boss is needed :
"Giant Bowser's Final Battle"
Of course, something like this doesn't really need a name, right?
First Phase - Simple Classic Bowser Battle. Just run past him to win.
Second Phase - Just like in NSMBWii, except you'll be climbing Peach's Castle as Bowser is chasing you to the roof. Not that long compared to this one, either. The exit is also an area where you'll be jumping up into via spring.
Third Phase - This is where the real battle begins. You'll jump up on the roof like how you entered the final boss area for NSMB2. Bowser will then jump up and roar like he normally does. But instead of lava rising and him chasing you, Bowser will instead start trying to pound everyone with his fists. All players can ride Bowser's hands up to his head, where they will ground pound it to deal damage. After 2 hits, Bowser starts blowing fire down at the players (he'll move his head over a player to make sure he hits). The fire will remain in the spot he burns while he starts trying to pound everyone with his fists like before, except his attack will be slightly faster (fire then disappears and he does that again in a different spot). After Bowser takes yet another 2 hits, he replaces his fist-pounding attack with an easy-to-jump-over swipe attack instead. As well, he'll start calling in Bouncing Para-Koopas in to attack everyone. Also, Bowser still does his fire attack, except his head is lower (to support jumping off the Para-Koopa's to land on it), and it now moves very slowly towards the player closest to the fire. After yet another 2 ground-pounds to the head, Bowser is finally defeated, shrinks down to size, and falls down below the area where Mario, Luigi, and the 2 Toads are. You then travel to a room below where Princess Peach is held and everyone is happy that Bowser is defeated!
...and then the castle has to be repaired during the credits as Bowser is carried out by either his troops, Toads, his airship, or shot out of a cannon.