I've been trying to make a custom rune, it's quite simple, it just staggers the opponent. I set it to stagger and nothing seems to happen, it tried setting the magic effect to paralysis, still nothing. I'm assuming the way runes work is the magic effect lies somewhere else, in explosion or something like that. There doesn't seem to be many option under explosion though, the closest thing I could find was a similar to a force ball explosion.

Any help?

Follow the trail of references that the spell uses.

Spell -> MagicEffect (FFLocation) -> Projectile (contains rune decal) -> Explosion

Yea, I know about the locations, I just don't know what some of them do exactly. What is rune decal though? I removed it and it didn't seem to change anything.