Arkham is encountered as the level boss of Mission 19. He has the largest health pool in the game which causes many players to struggle in DMD due to the need of heavy Combos and firepower.
You absolutely need at least 4 Holy Waters :
Vergil follows same steps except that he spams Yam Aerial Rave + PS
Try to afford Devil Star before the fight if you are uncomfortable with low DT gauge.
Aerial Rave + PS makes the boss pretty much impossible to dive compared to Dante's risk.
One big advantage on using Rapid-Stinger is Vergil's Rapid Slash which deals a lot of damage against Arkham.
Same story as previous phase except that you can't use DS and DT. Stinger into StarFall to approach before Aerial Rave PS spam.