I've said it before, but I have a personal attachment to the character of Grendel from Beowulf (thanks to Jon Gardner's novel Grendel) and I'm always a little twitchy about seeing him represented as a straightforward monster rather than an archetypal manifestation. The notion that his lineage of Cain makes him related by blood to Scandal is an interesting idea, but again, it ties Grendel down too much for my taste, makes him too simple. His perfunctory dismissal by Wondy's patented neck-snap doesn't sit quite right with me either.
Not that any of this makes this story less interesting to me; Secret Six is, and I suspect will continue to be, one of my favorite comics currently seeing publication. But any use of Grendel always makes me a little overprotective.