Is Hargrave supposed to be unbeatable when she has the black orb? the accept option? cuz she's pretty f*cking overpowered, brainwashing nuan and sable in one turn leaving me with all the useless characters, then killing them, and practically brainwashing a party member every turn. and if you do somehow get her massive hp down she starts a new battle immediately and at that point you only have like 2 characters left, then again the game IS, INCREDIBLY hard, what with the highest single damage i've dealt that wasn't crit was like 328 and that was oiled flame dance, really wish there were actual good weapons, the only good weapons i've gotten was the clubs from the clown cat lady, zweihander and ur something axe, the rest is jsut sword or knife or different weak whips. nothing ever breaks 100 in stat window
heck probably the most useless character, yterre can't even deal above 100 damage, only thing she's good for is ice once or twice then blow away from party so those who can actually fight are there, second worst is prob samona, two characters who only have any use if you sacrifice a party member to be either maid or puppet, ( most are level 8 btw)
You can block enemies from brainwashing your allies... by brainwashing your allies yourself with the Obedience spell. Lilina can learn this, and anyone else with Magic in their base class can learn it via the Copy Princess class. When Lilina reaches Lv10, she learns a stronger partywide version: Royal Edict. It's one of the most powerful moves in the game just because it blocks brainwashes on all three of her teammates.
Yterre is crucial in Hardmode's earlygame since Hardmode Nuan is not reachable (nor affordable) to the player at the start of the game, and Hardmode Jyla can easily defeat a party of three. Yterre can be recruited without a fight, which is just enough to tip the scales and win against Jyla. After that, though, it might be sad that Annie does her job better. Still, Yterre can use Magic, so she can use Obedience and Empower even when no maids are present.
Also, I'm not sure why you think Maids are weak? There's a very powerful Maid-exclusive weapon available in Hargrave Castle, and Maids have a 3-hit attack skill. They can also use the Ripper's Knife, which has the same Attack power (but not all the other stat bonuses).
Samona was very powerful to my recollection. Perhaps you haven't received her upgrades from one of the "abandoned" houses at West Beach. With that upgrade, she can have two instances of Flamethrower (one from JP, one equipped as an Attachment), both with 4 charges (she has passives that add charges to Puppet skills), and empowered by the Ruby Mage-Ring. On top of that, the upgrade from that house also unlocks new things for her workbench.
Look at this. Lilina can now open a battle with both Mass Barrier and Royal Edict, is immune to Lust and Brainwash effects because she's a puppet, and can spend her turns either healing twice or attacking twice (with more Attack than Nuan, and more than double the HP!) or doing both once each. This is with Samona at Lv7; puppets would match her level, but she has a passive that adds 3 more levels to puppets.
You could also have Nuan herself be a puppet and use Dirge (learned as a Skeleton Warrior) + Flame Dance in the same turn. Or Dirge+Dirge to bring her CP to near-max in one turn. Or Dirge+Drain to generate CP at the cost of HP, and then steal some HP from the enemy to replenish it.