He's actually the easiest boss in the game. Learn how to parry the first summoned sword. That's the most important thing in the entire battle.
Here's what you do:
- Parry Summoned Sword
- Basic Arbiter combo should get you to the first cutscene _____
- Shotgun the four Summoned Swords(one shot should do at anything less than medium range). He will either repeat this four times or just once.
- After his Summoned Swords cycle, he will do a Helmet Breaker, so you need to dodge(preferably jump, but only once) that first, and then quickly use shotgun to stun. From there, use Demon Grab and then Aerial Rave. If he teleports to do the air projectile slash after the first hit, use that extra jump and then use Demon Grab with Aerial Rave pattern. Believe it or not, he'll more than likely go into a predictable attack pattern from your pattern of Demon Grabbing him then Aerial Rave, which means he'll simply do the air projectile slash after falling back in the air from the 3rd or 4th hit of Aerial Rave. After a couple cycles, you get the next cutscene. _____
- Now he'll do his ground projectile slash. The same strategy of the above applies except that he'll also mix in Killer Bee attacks. So jump, grab, and rave. If he does Killer Bee, then dodge his attack and then do a two hit Hacker with Trinity Smash chaser. _____
- Next, he'll do Dimension Slash 5 times. After that, he'll revert to one of his earlier patterns, so all you have to do is wait for him to do the air projectile to do Demon Grab and then Aerial Rave.
- When he goes into DT mode, don't panic because you can use the same strategy as the above.
After you get used to parrying and his pattern, you should be able to get through this in less than 3 minutes without getting hit.