I'm fighting Yaldabaoth. I'm doing fine on him until he decided to use Divine Apex, I use guard,survive the attack but after that, because he has lost of weapons getting lots of turn and kill my characters.Also,I'm running low of SP or Takamedic HP when that happen. Is there a way before I fight Yaldabaoth,I go back to clinic to restock my medicine? I'm at level 69. I did ask Lavenza to heal my HP and SP before that and still running low of SP when Divine Apex happen.

Destroy his arms over and over, it reduces the strength of the attack.

I don't think you can go to the clinic, but if I remember right someone standing next to the door to the Velvet Room might sell you items.