Need to clarify the Ultima thing...

I'm playing the PSP remake and there is something I need to know. I heard that even though Ultima is called a white magic spell in the manual, its power actually relies on the caster's intelligence. I want to know if this is true, 'cause I'm really close to obtaining Ultima (I'm at the Cave of Mysidia) and I need to decide who should learn it - Firion (my white magic user) or Maria (my black magic user). Help. :cry:

You're probably already thought of this, but have you checked gamefaqs?

Intelligence and spirit are both irrelevant. Ultima pulls its strength from the casters weapon and spell levels. Your best bet is to give it to whoever has the most spells at the highest levels.