During the first battle, he is very annoying, and he does not flinch if he's hit unless you strike while he fans himself with his sceptre this is triggered by shooting him with a gun, but spiral and artemis are most effective. You are free to do your most punishing and powerful combos while he's doing this. After this, Jester vanishes and summons a flurry of energy spheres and behaves more like a circus ringmaster. He still won't flinch while doing this. The spheres can be unpredictable and hard to avoid, but he summons them in one of three attack patterns
Scrambled where the spheres bounce around the whole area. This is his most unpredictable attack,
Circulating, where the spheres move around the area in an orderly, yet slow and circular fashion;This is the easiest to avoid, and finally,
Waves where the spheres come from a single portal above Jester, but in quick, devastating waves of three spheres in all directions; this is extremely hard to avoid if you are anywhere near Jester. The only way to endure the waves unhurt is through timing your rolling and staying far from Jester while he's doing this.
The second and third battles are similar to the first one, only with three major differences
1:They can be skipped
2:Jester attacks a bit more aggressively
3:When about half his health has been depleted, Jester will summon a giant, smiling ball to ride and attack with.
When he summons the ball, Jester's arsenal of attacks will change slightly. Sometimes, the "ball" will shoot a bomb from its mouth. Another ability it has is the uncanny ability to use the spectral hand found on demonic door barriers to attack, usually when Jester uses his spheres, You can tell if the ball will use it if it appears to be straining something. Then, there are the four large demonic barriers the ball summons when Jester uses any sphere pattern. Finally, the ball has the ability to explode when you attack Jester with a Devil Arm before he attacks. Once you make your move, Jester vanishes. The ball laughs and explodes a short time later. Jester then summons a new ball. A quick strategy is to take advantage of the fact that you can actually make Jester tired while he's on the ball. Then, barrage him with cerberus aerials and avoid his attacks.
During the last battle, the ball has two more attacks: Jester will roll it around, damaging anything in its path, or he will bounce around the area with it.
It's possible to break the ball when Jester is fanning himself. Even though he will summon another one later, doing so will give you more time to attack
hope this helps