SE never tells us our role, they never really have since... maybe Aht Urghan. When it launched, they had their own ideas, but now the community shows them what we need, and they respond
RUN is a tank, but decidedly blink. I have face-tanked enough as it to say that we can bloodtank, but it's not pretty. We aren't DD, we don't have anything to really drive home damage. Lunge, maybe, in the right circumstances, when the stars align. But my Eva is good enough to go toe-to-toe with a good number of mobs. I was in Aby the other night, though, and yea, getting hit SUUUUXXXX.
In the end, RUN is a custom tank, primarily for weak melee casters. We're talking those mobs that end worlds with their spells. I facetanked the T2 and T3 Avatar-style mobs in Grauberg, Miera was annoying, and really I was a waste as even with dark runes up, it really doesn't make a difference. It was facing Gam that I saw my future. Resolution gave me enough damage to hold down hate even with the healer bombing me from time to time. RUN would likely do well with a THF Tricking to hold hate better, or possibly /SAM and try to ride Saigan. Other possibility will be one hander axes after the patch with /NIN, a sort of Magic Resistant WAR blink tank.
But yea, we are eva tanks. Get a MAB set if you want, but with no Lunge time reduction merits, I don't see us as DD's.