Until the end of turn, you gain control of target creature
As long as you can get some damage on Screaming Nemesis, your opponents are down a strategy permanently
While we are not the biggest fans of recent Blizzard practices, it cant be denied that Hearthstone is an extremely robust and in-depth card game
Its not enough to make a thing for one card, you need to make something that can be useful on five, ten, twenty cards, depending on the kinds of thing its meant to impact
Far easier to cast than the clunky Marshals Anthem, often cheaper than Triumphant Reckoning and Brilliant Restoration, and most importantly it brings back creatures
Since Skullclamp often draws cards the turn it comes into play and only costs 1 mana, its hard to remove profitably