Billy hasn't posted at all and he has a reputation for suddenly leaving RPs. In fact, I actually have a list of people I probablu wouldn't accept signups from because they're unreliable when it comes to posting. Least from my experience
The first post hasn't been updated in a long enough time on Children of Legend for Water to be taken. Ground has someone working on it, but they've said that If someone else finishes on first they'll give it up. The fully open ones are Rock and Bug. Poison may or may not come up, if the GM gives their second character's type to Treeconator. I am fallible though, so it might be worth it to double check in the thread. ^_^;
Hey, I don't know if you still need help or if DVB is helping you, but Hekate (or Hecate or whatever, variable spellings depending on translation and all that) is a goddess of magic, so you could have powers as simple as spell-slinging that grow progressively stronger as the RPG goes on. You could also consider shapeshifting, as Hekate is an archetypal threefold goddess associated with the changing faces of the moon, and her followers in the myths (Cersei springs readily to mind) turned men into animals. Pigs were popular. So animal dimorphism perhaps?