Does Vanguard come in rested or active off an Akshan effect?

When an enemy gear is moved to your base by Akshan, Mischievous, it retains its current state (ready or exhausted).

According to RiftJudge FAQ #9483 and the general rules regarding control-change effects:

• Control-change effects (like the one created by Akshan) change which player controls the object, but they do not change the state of the object itself.
• If the gear was already exhausted when it was moved to your base, it remains exhausted under your control. If it was ready, it remains ready.

As a reminder, because you are now the controller of that gear, you are the one who decides when to ready it (during your own turn) and you are the one who can use its abilities.