[Autumn]

Ring of Thorns - -10% HP, +3 Power to All Weapons. - - 4*

The trade off is nowhere near close enough to even be considered worth it. Maybe if it gave +10 Power? +20 Power? I'm not sure, but definitely not worth +3 Power.

Or reduce the health drain and put the power bonus to something reasonable.

My only concern for this one is the possibility of Multi-shot gun weaponry meshing too well with it, since it is straight damage per shot and not just weapon power, I'd just like to note out thats a possibility is all, and can be adjusted for beforehand.

Spirit Mirror - Reflects the first enemy projectile that hits you. - 5*

This item is probably totally fine. Though I think it'd see more use if the reflect regenerated over X amount of turns. Maybe 3 or 4?

Pretty much this, I've wanted the reflect projectile buff to be renewable in some fashion, but not in an overpowering way to archers or gunners, I was sorta thinking shields at first (Mirror Shield would be a cool item), but if the spirit mirror regenerated its Mirror status, or even granted a high cooldown skill that granted its status, that'd be wonderful imo.

Frosttouch Gi - Cloth - 1 Defense, 6 Magic Protection, 5 Evade, 5 Weight - Gain a chilly ice barrier that deals 15 unresistable Ice damage to attackers for 2 rounds after casting an Aquarian spell. - 9*

Probably the worst effect out the 9* elemental gis. The lightning one gives +15 Critical after a Nature spell. The fire a whopping +15 Strength after a Nerifian spell. Wind with +15 Evade after a Sylphid spell. Meanwhile this thing does an incredible 15 unresistable Ice damage after getting attacked after you cast an Aquarian spell.

I'm not sure what a good compensation would be but I'm sure someone could think of a better one.

I think each of the elemental gis can be a little on the weak side, I think an excellent way to compensate is to give them up to 30% elemental resistance to their respective elements (Like how Whynnesfelt/Irisgold etc. are), this'd be a massive boon, as for Frosttouch Gi specifically, it can deter basic attackers if the on-return damage was a little higher, probably up to 30 as well or so.