Charlotte
*The group, upon reaching the level of the giant heartless, noticed that there was something strange on the clocktower. It looked like a glowing keyhole. Asriel's attack would only make the heartless notice the group, as it prepared to fight them all now.*
Peter
He would see the heartless preparing to attack them but he would see a giant keyhole Could that heartless be guarding that for some reason he then plan to examine it after they were done with the heartless he would point starlight at the heartless and cast fire four times in a row 
**Cast fire**
**Fire damage:260 x 4 x 3 + 2.5 = 5720**
MP;140 -80
AP:114 ->99
Samuel
"Hmm I can lock that baby up, you guys guard me until I'm done" 

*He starts to fly abit higher now that they are busy with that big heartless and starts charging up the key beam*
Elizabeth
"Thats the symbol Sunset described to me! Alright then, lets get rid of the Heartless first!" Twilight told Rainbow Dash and Fluttershy before dashing towards the giant heartless with a flurry of strikes to its head. After the strikes she charged up both of her Keyblades and fired Ragnarok missiles all over the giant heartless to try and damage it alongside Mehki's Fire casts. Afterwards she used a new spell in Silence to make the giant heartless unable to use magic for a short bit.

Ragnarok: 55 x 10 x (5.75 + 7.5) = 7,287.5
Silence: No Magic For 1 Turn


MP: 170% 155%

"Lets try another approach for this baddie!!" Rainbow Dash said to herself and then made her Keyblade glow, activating Attack Haste before she pelted the giant heartless rapidly with a Dodge Slash smack to its head. Afterwards she fired an Aero onto the heartless's back to try and knock it downwards a bit.

Attack Haste Activated: +10% Attack And Speed For 5 Turns

Dodge Slash: 21 x 10 x (2.0 + 3.0) + 10% = 1,155
Aero: 28 x 10 x (1.0 + 3.0) = 1,120


MP: 130% 115%
Edwin
Fluttershy then fire an Ice Burst towards the giant heartless's head as well, as then she used Time Splicer to zip around the heartless and slash at it multiple times in circles.

Ice Burst: 41 x 10 x (3.0 + 4.0) = 2,870
Time Splicer: 28 x 10 x (0.5 + 6.5) = 1,960


MP: 140%