The thing that throws me off about Hamadria is the base size. Normally I'd imagine a dryad to be a small model. Maybe it's got the whole tree on the base?
edit: or additional satellite models a la Dinah or Arias Vayu?
Base size is just a guess due to the price. But if it is a Wood Nyph maybe its has options to be different types of wood nymphs like Apple, Willow, Oak, Yew, Birch, Holly, Hawthorn. While being Neutral would be a base faction as some of those types are Light while others (Hawthorn) are dark. But that seems much for just a low level monster. Only Type-005 is really that low according to the TWWAU.
As for Legion he is now the number two must get (after Sigma Zero) unit. Of course I'm likely to get all of them but still if I had to choose, I'm super excited about this one.
On another note if they can get Legion in I don't see why they couldn't get a Necro Golem in. I think it would be even easier since its a borrower. You know don't have to show the whole body just part of it exploding out of the ground. Black Sun needs a Large base units anyhoo.