While I have to wait for Khans of Tarkir to hit Magic Online to kill people with Jeskai Ascendancy, now is a great time to get some practice in with another fast combo deck that doesn't need any cards from Khans: U/G Amulet of Vigor. I believe the list I'm playing is fairly standard, but I'm playing with Ancient Stirrings rather than Simian Spirit Guide, going for consistency over speed.
The black deck doesn't interact with you when you try to go off; they have to prevent it with discard, but their clock is so slow that even if they have Thoughtseize, you can draw out of it.
That first game demonstrated what my previous opponent was trying to do. In the second game, my opponent didn't have targeted discard, and I had a draw that could actually go off (note that these have been surprisingly rare in my experience, but the deck seems to win anyway most of the time). For the third game, my opponent just singlehandedly lost to Leyline of Sanctity, and while I don't think their plays made any sense, there was really nothing they could have done.
So that ended abruptly because my opponent disconnected (I assume unintentionally), but it looked extremely likely that I was going to win in two turns from there. I'm not sure my opponent needed to commit as much as they did in the second game, though the fear of losing out of nowhere is very real. As it played out, a little hate went a really long way. Between that and the speed of the combo, I think this matchup is pretty favorable if they don't have Blood Moon.
Discard, counterspells, and a fast clock is definitely the exact combination of cards I'm hoping not to play against with this deck, but still, there were a lot of draws that could have won the first game for me at various points, and in the second, my Leylines just came at exactly the wrong times.
Overall, I think the deck is pretty good, and in particular, better against Thoughtseize than its reputation may lead you to believe, especially if the opponent doesn't support it with a solid clock.