Theron was still a bit focused on the last of the three techniques when he looked up and found Blackmaul there. Of course, he recognized the young man with exceptional quickness, and he was even faster to sense that his aura was now that of someone in the Quasi Cloud Resonance Realm.
However, one would have never guessed by his expression that he recognized Blackmaul at all. His thinking speed was exceptional, and his Third Eye was still far superior to those of the same level. Even if he was stupid enough to express shock, he would have hidden it so quickly that even the likes of Blackmaul wouldn't be able to sense it.
Blackmaul, though, saw something completely different. He hadn't seen Theron's full face back then, but a piece of the mask had fallen off. In addition, this Theron was the exact same height as the Theron of back then, even though their auras were vastly different.