Yeah, I have seen some of those animations, but can't remember which author it was from, can you?! The leave animation IIRC is simply particles with leave textures/ meshes, not that difficult. There is even a description on Amael's modding site how to do this:
http://miolnir.co.uk/amael/
I was watching "Spawn" the movie and the animated series recently and I thought to myself it would be nice to have some kind of armor similar to that. Especially that shroud he has. I will try to make an animated one, which is synchronised with the different idles, for example if you jump, the shroud forms up like wings or while sneaking covers you like some kinda shield. I'll try that with different shapekeys. I was also thinking of an armor made with shapekeys and keyframe animation, which is made of dozens of single parts and puzzles together as soon as you equip it, but I havent figured out how to get around the problem that the bodypart gets replaced as soon as you put on a piece of armor. I'll have some brainstorming!!!;)
TheDaywalker :rock:
Unfortunately no idea for one with leaves, sorry. I've been trying to find it myself, but never did. If I remember correctly, they were part a some very large weapon compilation (not HELLUVA)
However, I think there is one mace that changes textures of electricity that is part of HELLUVA, it's a mace.
EDIT:
yes, it's definitively HELLUVA, 1 handed mace if you're interested in downloading http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=6589
For easy locating, if you do download here is the pic http://planetelderscrolls.gamespy.com/fms/Image.php?id=67493