Games : Does Poison damage scale with Magic?

Sephiroth is a pretty useful character. He has great Attack and Speed and can even use Black Magic!

But... He's not very good at that Black Magic stuff. His Magic stat is... Let's be generous and say "in need of improvement." Unfortunately, he can't equip most of the good magic boosting gear. Fortunately, spells like Gravity and most status magic don't scale, do it's still useful!

The question is though, does Poison scale? It does pretty devastating damage when I have Rydia cast it, but I have no idea if it will be anywhere near as great coming from Seph with his low Magic. Is Poison scaled or fixed?