Re-reading the updates a bit, and this is a bit old at this point, but given the "anime bullshit" tag I'm going to assume that some sort of Marshmallow Hell was going on in this scene and that's why she called VM fat.
You manifest before the caster--a child who yelps as she drops the staff--her Power lashes out--but you draw it into your hand instead of allowing it to sink into and destroy the caster. "None of that now child" You gaze upon the dusky youth--and you know them to be one now.
You… Their voice wobbles, and you kneel down and take them in hand and give them a nice big hug. "There there…" You pat them on the back. "Everything's going to be okay…"
... fat the voice murmurs--you freeze for a moment, and let your watery eyes be missed through the lack of perspective. You're not fat! You're perfectly healthy!
It's just that you have to appeal to more than the tastes of the Eldar!
Still, it hurts to be called that!