In Media Res
Regain Mana, Level «LEVEL»
Regain Mana equal to the cost of a spell of the level of the effect when you next cast a spell.
Regain Mana equal to the cost of a spell of the level of the effect when you next cast a spell of the «ELEMENT» element.
The next time you cast a spell, you gain round(38.1 + 2.3375*LEVEL + 0.01125*LEVEL^2) MP, and the status ends. For this to work, the Spell needs to deal at least one hit (so, no, guest-summoning spells won't work) whose Type is Magic.
If it only applies to spells of a specific element, then it only applies to spells whose database element -- like, what it shows in the shop or in the quick-cast bar -- is the proper element. For example, Spellcraft will NEVER get the bonus, since it's Neutral.