if I swap a unit using green Azir's ability and he grabs Pendulum Blade off of them during resolution, does he get the addition +2 from the blade or does his move resolve first

The ability of Azir, Ascendant resolves as a sequence of instructions executed in the order written, per Rule 157.1:

"[C] : [Action] — Choose a unit you control. Move me to its location and it to my original location. If it's equipped, you may attach one of its Equipment to me. Use only once per turn."

The Resolution Sequence

1. Movement: Azir moves to the target unit's location, and the target unit moves to Azir's original location.
2. Attachment: After the movement is complete, if the target unit is equipped, you may choose one piece of its Equipment to attach to Azir.

Effect on Might

If the Equipment provides a bonus (such as +2 Might), Azir will receive that bonus only after the Equipment has been successfully attached to him during the final step of the ability's resolution. Because these instructions are part of a single ability, the movement occurs first, followed by the attachment.

Note: I could not fully verify this ruling against the retrieved rules, as specific card data regarding the "+2 Might" effect was not present in the provided context.