On the concept: awesome! I'd really like to see this card with a picture like the grudge spectre!
Like this:
On the mechanic: i think it should be cleaned a little. I did not understand well, if Misery|Woe takes 1 damage what happens:
every opponent creature take 1 damage1 damage is redistributed randomly over opponent creatures
I think the second solution is more easy to balance, since there is not damage multiplication.
Also, i think it's bad to have an immortal creature. Just give it really big HP and no attack. Also, this way you can take away the
drain every turn.