What should I do with a Black Magic user when I run out of MP? Does that character need to fight at that point? I'm having trouble continuously casting black magic spells and having enough MP for the whole dungeon/tower that I'm fighting through.

Also, I thought this would work, but it doesn't really. If I get low on HP, and get an HP increase, I'll try to Cure a little and then drop down again, to gain even more HP. This unfortunately doesn't work. Should I try to Cure back up to 50% HP & then drop down again?

Any tips for increasing MP?