Starting at floor 601 and rushing is the fastest way to cap your Resistance Power (RP).
Complete the main story and access the bookcase in Hades. Labyrinth of Chaos
To reach high floors (600+) quickly for superior loot (level +31 to +33 gear), avoid non-mandatory battles. Starting at floor 601 and rushing is the
"Haste/Increased Priority" skills are essential to counter high-AGI enemies in higher floors. 3. Key Superbosses and Encounters Labyrinth of Chaos/Tips - Monster Girl Quest - Miraheze or after reaching them
You cannot save inside except after boss rematches. You can start from floor 1, or after reaching them, from 101, 201, 301, 401, or 601.
Once RP reaches 20,000, additional RP converts to UP, allowing you to buy rewards from the White Rabbit, such as Legendary Gear Gachas.