I'll have to say I'm very tired of Darkness getting all these manipulation-based cards; it has more than enough tricks up its sleeve already. It could fit Death or Water though, and Death would be most in need of versatility as I see it.
As for the card itself, not only countering a SoG, but also making it do almost unavoidable damage is very, very good in the upped environment. Not to mention on an Eclipsed Vampire. 4/3 cost might work, but I'm inclined to raise it to 5/4 since it's not "Other". Actually not sure if it would be enough.