Mana
The center of all things magic. Like it or not, everyone runs out of mana quickly. Here's some tips and stuff to regenerate mana.
What to do/not to do:
1)
Don't use
all your mana at once, it'll (usually) cost you your life
2)
Always bring some Mana Potions (any size), so you can get some more
3) Use Magic Armors if you're a real mage, don't use other roles' armors
Tips:
1) Get a Mana Flower as soon as possible so you don't need to press M (or your preferred hotkey) manually, and it'll add your mana by consuming potions as soon as it'll run out
2) Bring 2 stacks of Greater Mana/Super Mana Potions so you'll never run out of mana quickly
3) Get a Crystal Ball for the Clairvoyance Buff (increased mana cap)
4) Get some Mana Regeneration Potions, like
@MegaMage314 suggested. It'll increase your mana regen rate
5) Get some mana related accessories, it'll help conserve your mana/increase mana (Band of Starpower, Celestial Magnet, etc.)
Those tips should help you have
infinite mana for your Last Prism. As long as you have coins, you'll have a steady supply of mana