What should my third materia be?

[Tridus]

VIT is also an option. Not going to lie. I didn't think about putting it on left side equipment. I usually only save it for right side.

Though again VIT is like PIE. Anything above what you actually need is sort of a waste, but it's still an option regardless.

VIT is a super odd one because most of the time it will do nothing at all. Every now and then it causes you to survive something that would have otherwise killed you, and at that moment it's the single most powerful thing you can possibly have. Nothing boosts your effectiveness more than not dying.

You're right, of course. It's not something you want to pile a ton of. But if you have nothing better for a slot and you have a lot of close calls, it can really show its value.