First, he closed his eyes and exhaled out all the air inside his lungs. Next, he wrapped his body with a thin layer of magic that rejects the gravity and any other external forces on him. The moment his body starts rejecting gravity, his body began to float.
Yui was astonished by this and started searching his mind logs to find out what he did. After some tedious searching, he finally found out and was completely dumbfounded by it.
The logic was pretty simple. But executing it for a long time was difficult.
What Aryan did was first he wrapped his body in a simple barrier.
The barrier didn't have any special properties except protecting him from normal harms. Then inside his mind using the Grimoire of the 8th sage (Former twin dragon grimoire) he created a spell that could send the gravity and external forces to space where he could store them and use it at any other time.