You are right on top of the boss as soon as you load the save. Just jump in the air and mash square,you will kill him in 1 hit. Trophy given during the ending.
Perfect Win Save
https://mega.nz/folder/n48RmToA#-NxYTznPOMVUO5hP13HIPg/folder/n80VEKzJ
Perfect Win Save
https://mega.nz/folder/n48RmToA#-NxYTznPOMVUO5hP13HIPg/folder/n80VEKzJ