King's Field: The Ancient City Cheats

Saving the game:
Remember that long uninhabited hallways, sparse enemies, gigantic openings, slow combat make 30 minutes of game time last several (real-time) hours. So be sure you save the game at every moment possible.

Remedy:
This is quite a bit better than purity and you can level it up by using is intermittingly and/or when you become poisoned.
User Cheat by RPGamer

Leveling up magic:
There are two places where you can level up most types of magic. These places are the Forest and the Golem Sanctuary (City Tower Level 2) The Golem Sanctuary is where you want to level up the OUT OF CONTROL spells such as tornados, volcannon, meteor cascade, etc.