[Cogster]

There's no such thing as a permanent evasion buff in the game, and there likely wouldn't ever be one without some heavy clauses, considering that long-term evasion buffs that build up already exist. Take for example two pretty popular classes Shapeshifter and Verglas.

Let's take a closer look at Shapeshifter, which grants 8 evade per chaotic form (youkai evoke). This class already has a momentum refund mechanic built into it, allowing you to chain up to 4 evokes at a time, resulting in 32 evade off the bat for one round. Now, consider Verglas, whose hare stance provides 5 evade for every instance of ice damage you deal in that stance. This effect caps out at 30, yet you can hit the maximum threshold with just two of its moves, one of them being in Hare Stance itself.

This, along with the fact that you're often racing against an enemy who can either dispel all your progress in one hit (RUNE MAGE) or fighting against another evadie that took one round to cap its own evade, its kinda clear that there are some issues with this thing. This doesn't remove the necessity whatsoever in grabbing the evasion buffs (Like distortion or ring of pearls) as a Wind Mage Spellthief, nor does it add anything to existing evasion engines classes already provide. The momentum race isn't favorable to this thing at all. 

What made Windswept Gi so strong in the past was how efficient it was in the momentum race. People could cap their evade immediately for three momentum by using Fortune Wind.

The only strong use case I can see for this is where it acts as a safety net for anyone trying to dispel buffs you actually care about, since there seems to be no cooldown to it.