First, raise your defense and attack, Urh, A lot! Then, take magical edge in one hand, mini shooter in the other. Take down fireballs using mini shooter, Defend the electrick forces or thunders with magical edge's reflection mode, Defend yourself by magic armors against dark projectiles and ice cubes(although ice cubes can be dodged by jumping).
Magical ball throws fireballs, then uses thunder, then ice cubes, then dark projectiles, then uses light that heals it by 10 percent. Here's what you need to do to take it down. First, You must take down those fireballs. Then reflect the thunder with magical edge's reflection mode. A peace of magic drops right there. Go far away from it, Turn towards it while aiming your mini shooter(since it's a long ranged weapon). As soon as magical ball reached in about 3 or 4 tiles to the peace of magic, Hit the peace of magic with your gun. It explodes and takes 20 percent of magical ball's health. You guessed it right. You need to do this 10 times if you are going to kill him with this technique. Because each time it takes 20 percent hp from magical ball, Magical ball heals itself by 10 percent.
Have fun killing it!
Oh huge spoiler, Maybe:
You can also run an old version of the game, hit the ball just onece with your chain sword or possibly snake chain, And it's frozen! Go hit it with the magical edge until it dies!