In short, soar wrapped Eldrian in a net of ether, which was connected to the wings. The wings then produced lift, and through the net Eldrian was lifted into the air. When Eldrian equipped the cloak, the net disappeared, and it felt more like the wings connected to his back.
There were naturally limitations in this method of flight, but it was far, far simpler than the flight magic Eldrian had been attempting to learn. The trick, however, was finding a way to connect the wings to his person. Since his own ether control couldn't manage his weight.
If he could, Eldrian would simply move himself about with ether as he did daggers and other items.
Something was special in this net and the connection that the cloak made. Sadly, Eldrian couldn't figure out their trick in just a few hours of test flights and analyzing of visible magical patterns. Even with mana sense showing him more than the average inspection skills.