Thank you so much it workd as for what comes later im sure i can handle it.You need to use Coffin Breakout 4 times in a row. You will get an in-battle scene where the boss taunts you and pulls you back in after doing this. On the fifth turn an invisible option in the menu will appear - it's very obvious - and selecting that will win the fight.
Note that every time you lose a fight in this game you get a semi-permanent penalty when fighting the same type of enemy and it carries over even if you reset or use a new save file. That means if you've lost this fight a lot of times it might be difficult to survive long enough to use Coffin Breakout 4 times before hitting 100 Lust (which will stop you from using struggle moves and thus lose the fight). I recommend drinking tea in the break room and equipping anything you have that reduces lust damage.
There is a guide on F95 zone's Shrift discussion page, but I do not believe I have enough posts to link it yet! Good luck!