Welcome to the overlord of Theros block. After day one of Pro Tour Journey into Nyx, we know a a few things about the format. One is that it's diverse. Aggro, control and combo were all represented well on Day 1. But one thing flew above them all.
It wasn't difficult to predict that Sphinx was powerful and would find a home, but what was maybe surprising is just how dominant it's been. Most games have been decided by the 3/5 flier, specifically which player has the most on the field.
Could it make an appearance in Standard to replace Aetherling after Rotation? I wouldn't be surprised, but you also have to keep in mind that there's no Supreme Verdict or any other Wrath clone in the format, which makes Sphinx nearly unkillable.
So I'm not sure this will be tearing up Standard anytime soon, but I do expect it to continue tearing up tables this weekend.