[Valerius]

I like Grendelkin as well (though most of the comments I've seen haven't been impressed with them). A couple things I'd add to what has been mentioned above is that those high HPs come without an undead/demon/magic being tag (and the counters those tags open up). And that Grendelkin have darkvision 75, meaning they won't have their attack/defense cut in half when Darkness is cast, like so many non-undead/demon summons do.

But Wendigo do sound interesting - I'll have to take a closer look at them.

I really like Treants but I've only summoned one. I just can't justify spending N gems on them instead of forging gear, fueling globals, GoRing SCs.