Let's move on with Arkham's spawn. I'll use gifs captured by myself during my game to help you readers understand the tips better.
These are those floating fish-like creatures Arkham spawns during his boss battle, while he retreats.
Now, they are indeed annoying and lots of newcomers to the game struggle against them, cause their attacks might be pretty hard to predict, cause the animation of the simple floating and the actual attack are very similar.
- With Dante, a great weapon to use against those little f*cks is Kalina Ann. The bazooka. Just wait until they begin to gather in a pack and shoot them. Use Trickster moves to avoid their attacks. Remember that the jump animation's got invincibility frames (you won't get damage during the jump animation), so if you don't want to use Trickster in the battle, and you prefer another style, just jump often.
- With Vergil, Yamato and Devil Trigger Explosion are your best friends.
Fight Arkham varying your attacks and use taunts to build your Devil Trigger gauge, so that when he retreats and his spawn show up, you can perform a full power Devil Trigger Explosion to obliterate all of those around you (wait for them to gather around you first, of course).
As for Yamato, Rapid Slash is excellent to use, cause it will hit any enemy behind Vergil as he charges forward, killing some of the spawn in the process, or weakening them a lot. Oh, and Vergil's got jumping invincibility frames as well, so JUMP!