You...mean the Ndesu, right? All you need to do is be fast with dodges, and that's it. There are way harder boss battles on Pro. Two on two fight (because Sheva gets killed by Jill so easily, you need to yell "Come on!" ALL the fucking time so she stays beside you) and Irving fights can be quite problematic. Although I killed Irving without needing more then 15 or so tries, which is cool. As soon as you get hit, go for "Restart" because the AI won't ever get to save you on time, especially on Irving boss fight.