[Autumn]

Alright well flanking is part of this whole mechanic that sort of promotes having team members to assist in some way, the flanking stat unfortunately seems very bugged on the character screen right now but it does work properly mechanically, I can explain how it works currently so that a lot of confusion is cleared up, but flanking had to be nerfed a very long while back just to make it so that building dodge wasn't completely worthless either, that holds true today, especially since afterimage's recent removal.

Flanking is equal to 25% of your scaled GUI currently, you gain 100% Flanking bonus versus targets at their sides, and 200% while you are flanking their back, effectively meaning you gain 50% of your GUI as hit at their back instead.

This can translate well, it does mean that while you are completely alone, you gain up to 50% of your scaled GUI as flanking, with 60 GUI that'd translate to 30 hit which is PRETTY good if you're building SKI and LUC as well, which you absolutely should since they're not only the critical chance stats but also the hit stats, so you can't just give it too much power either.

As I said earlier though flanking necessitates teamwork as a core mechanic to gain the full bonus, whenever you have an ally at an opponent's side or back, all flanking bonuses are doubled again, meaning that you gain 50% Scaled GUI at their sides and QUADRUPLES to 100% Scaled GUI at their back, you can abuse this slightly by being able to summon allies mid combat, for example a butterfly summoned by a papilion DOES count for this effect, so you don't have to be paired up with someone either.

GUI is not countered by dodging, you simply just don't have enough hit or the enemy has too much dodge, also armor of eyes does not block the actual flanking hit bonus, it only blocks flanking damage granted by Rogue and Void Assassin skills, so it does not actually effect your hit in the slightest here.