This Seeking Tech guide will explain how you can recover MP and farm for Magla Pills in the Dragon Temple dungeon in Metaphor.
For the first step, you should make your way to the Bounty of Relics section of Drakongrace Shinjuku. The room directly left of the Magla Hollow has a trance crystal with level 37 enemies.
If you are level 40, then you should equip your hero with a Mage or Wizard Archetype and then head to a corner in the small room. You can then attack when the enemies fly to you. Your party will recover 1 MP for every defeat. The moth enemies may also drop Magla Pills, which will recover 20 MP when used.
To increase the drop rate of the pills, you should equip the Lucky Find skill from the Merchant class.
If you already destroyed the crystal, then there should be other crystals to use in the deeper areas of the dungeon.