And read the Notes.
Wasn't written in the notes when I asked.
It also effectively kills your creatures and summons the same creatures on your opponent's side.
As so often with cards that influence both sides, you forget that the player using this knows of the negative impact this card will have on his own creatures and will adjust his deck accordingly.
This simply would never be used in a rush or any other deck with creatures - unless as a fun deck that isn't supposed to be strong - thus the drawback is irrelevant. Unupped, it's clearly a card for stalls only.
And upped, it doesn't even have that drawback anymore.
5% for a stackable chance for an instant kill even for immaterial creatures is ok, 5% for a stackable chance for a PU even on immaterial creatures is ok, 5% for both in one card I find to be too strong.