Anyone here knows how to win the mansion boss?
Do you mean the headless samurai lady?
For me it was just standard attrition battle. Keep the HP/MP regen buff up all the time and play defensively. I mostly build up TP for the 100TP special attack (also comes with heal and status clear)
This boss has a counter mechanic. It's been a while since I played so I don't remember the exact animation, but there are certain moments in the fight when you need to avoid dealing damage.
I tried to rush things in my first playthrough of the fight and just ended up killing myself.
What worked for me is to just treat it like a control fight and take it slowly. The boss cannot outtempo you unless you push it into the next phase before you are ready.
Prioritise keeping your HP up, don't worry over boss HP. I remember I was skipping my turn a couple times by spamming the HP/MP regen buff, heal or guard until I got the right timing on the boss' TP gauge.
Try to delay using the first cast of the 100TP special for as long as possible since it's a free reset and it can bail you out in a though situation.
My approach was to build up TP so I can easily do the 100TP move in the next 2 turns if necessary to remove debuffs. Even if your HP reaches 0, the regen buff should keep you at full MP, ensuring you last enough until you get back to 100TP so you can reset with special. Keep in mind only first cast of the special is to full HP, the other ones will be smaller heals, so you'll need to guard/dodge and find gaps in between enemy's turn to reapply regen buff and cast a heal.
I'd keep an eye of the boss's TP gauge, especially later in the fight when she starts using new moves. When the gauge is low throw in a 35TP 3 strike move, otherwise regen buff > dodge/guard > heal. I prefer guard over dodge because it yields a net increase in TP.
When the boss starts flashing red, the frequency of its moves becomes overwhelming. Make sure you know what the animation for its counter looks like. At some point I think it does an offensive attack and ends up in the counterattack stance after. You might want to keep an eye out for that.
When the boss is red, just make sure the timing is right and unleash your hardest hitting move, that should finish them off.
