Curtain Call is really good in gauntlet. Send an Agent is the new hotness.
The powerbase is almost as stable as mono time. Sometimes you'll miss turn 2 because of depleted power, but that's about the extent of it. Twinned Spiteling can be played on curve 80% of the time, and Curtain Call is always playable by the time you need it.
Thoughts?
Curtain Call is mostly a great way to turn a contested board into a blowout. Even if you don't have a good board for it, it's a fine combat trick and much-needed life gain. I have it at 3 copies here since I rarely need more than one, but the first copy pretty much always gets value. It's especially good for getting out of burn range when we stabilize at low health.
I could see 4-drop Vara being a good option too. Let me know how it goes.