Historically, Delphinus is the final/hardest boss in a Neptunia game and Superdimension Neptune VS Sega Hard Girls is no exception. Even though Delphinus is a hard boss, creative gameplay can make her fairly easy.
- Must be in New Game + because that is the only way to unlock this fight.
- Use the exceed damage formation and only have Segami and Mega Drive enter the fight.
- Segami and Mega Drive should be level 99 with at least one subclass at level 50. Mega Drive must have her second subclass at level 50. This is best done with all three subclasses at level 50.
- One STR Booster Z item.
- Full fever gauge.
Please note, this must be done is precisely this order or it will throw things off and ruin the tactic.
Start by having Segami move next to Delphinus and have her transform into Dreamcast. Have Segami use STR Booster Z on herself and then end her turn. Have Mega Drive walk under the fever star and cast tired on Delphinus. After that jump to start fever time and then cast charge on Segami. Use dream blade special on Delphinus and end your turn. Cast charge on Segami again and end your turn, followed by using dream blade special twice more as Segami. As long as you do everything right and have enough power this should be able to defeat Delphinus before she can even counter.