*slaps a leaf hat on Frosty's head*
Welcome to the PTGT (Power To Grass Types) club. While Grass' weakness to Ice does make sense, I think that's the one weakness that should be removed. I mean, Ice is already strong to flying, ground, and dragon, meaning any common water type can take those types down. Some people say that Steel should've had a water and/or electric weakness. I think it would be great if we removed Grass' ice weakness, so the poor darlings wouldn't have to fear some silly water-type's ice attack. Just make ice normal to grass, that's all I'm asking.
Oh yes, more about Morinu: I never made a finalized pic of it, but the way it fits with the other legendary beasts is that after the lightning struck brass tower, and the fire burned, and the water put it out, Morinu brought the surrounding plantlife back. Then again, this life-giving kinda conflicted with Ho-oh. This is why Morinu is a fan-made :D.