what team are you using? i find th last stage too frustrating to be fun to repeat thousands of times to farm the two sisters,but maybe there's an easier team than the one i'm using
I'm using Double Sengoku, Arlong, Alvida, Summer Perona, and GP Usopp, but Sengoku isn't required. The main goal is to have:
-GP Usopp
-A damage reducer
-Either a second damage reducer or boosted HP, be it from a captain (SW Ace, Legend Jimbei) or an advanced ship (Coffin Ship, Bike, Striker, etc)
-Anti-Despair helps, though you don't need to be level 3 or anything. You won't be doing good damage for a few turns anyway, so you might be able to get away with none at all
When you get to the sisters, they despair you, give you shitty orbs, and put up 3 turns of defense and debuff resistance.
-Target Sandersonia (the green one) and attack, mostly just to clear out the bad orbs.
-Sandersonia will now be at 1 turn. Use a damage reducer or tank Sandersonia's hit if you have boosted HP.
-Marigold is now at 1 turn. You definitely want to use a damage reducer since Marigold hits hard.
-After her attack, the defense/debuff shields are down, and your despair should be gone. After using Usopp, Sonia will be at 4 turns and Mari at 6, which should be enough time to burst them both down. Mari will poison you at under 50%, but you should only be a turn or two away at that point so it won't matter.
So for an example, a slasher team of Double Mihawk, Arlong, Mr. 1, a QCK slasher, and Usopp using the coffin boat would probably have no issue (especially since you'd have Mihawk's health cuts to use).
I think I won't farm those sisters. I got Marguerite so I'm done with this island for now.
Yeah, I wouldn't classify either as vital, but I like getting story characters so I put myself through the suffering.
Marigold is our second Badly Poison/Venom user, so that's something. Somehow all the Venom users are story characters.
Sandersonia has a conditional damage boost against Venomed enemies, which is unique, but I don't know that there's any good place to use it at this point. She's obviously designed to be used with her sister, but until we get a DEX Venom user, she probably won't see any play.
Margo's easily the best character in this island, since she's a solid boost for anyone who runs Shooter teams and doesn't have SW Franky.