Akshan, Mischievous

What happens when my opponent's Akshan, Mischievous steals my equipped Shady Spectacles? What happens if they want to copy Aphelios?

If it was attached to a unit, the equipped unit loses its copy effect. Akshan will then become a copy of a friendly unit of his controller's choice. If he becomes a copy of Aphelios, his ability will not trigger.

This question deserves a bit more depth. As of the Vendetta rules update, we have clarified how effects like Shady Spectacles and Svellsongur work; they are replacement effects that replace the event of the equipment being attached to a unit with that event plus whatever their effect specifies.

In the case of Svellsongur, the resulting series of events will be:

Attach → Copy the equipped unit's text to Svellsongur's effect text for as long as Svellsongur is attached

For Shady Spectacles, the resulting series of events will be:

Attach → Choose a friendly unit and make the equipped unit a copy of that unit for as long as Shady Spectacles is attached

These events are not simultaneous. The attach event executes first, and then whatever event is instructed by the replacement effect is executed. Thus, the answer in the Spiritforged FAQ is no longer true: if you attach Svellsongur to Aphelios, he will not trigger twice. Svellsongur doesn't have the copied effect text when the attach event executes.

Similarly here, if Akshan nabs Shady Spectacles from an opponent, it will attach and then make him a copy. If his controller chooses to make him a copy of Aphelios, it's too late by that point for his new triggered ability to see the attachment event; it's already been completed.

Relevant Rules: 369.1., 370.1.b.1., 370.1.a.2.

359.3.e.16. If a Delayed Ability's duration has ended before it was generated, the Delayed Ability is not generated and any instructions related to it are ignored. Example: Targon's Peak is a battlefield that reads in part "When you conquer here, ready up to 2 runes at the end of this turn." If Targon's Peak is conquered during the Ending Phase after the beginning of the ending step, such as via an effect like thrill of the Hunt, the delayed trigger will not be generated. Example: Akshan, Mischievous reads in part "When you play me, if you paid the additional cost, move an enemy gear to your base. You control it until I leave the board. If it's an Equipment, attach it to me." If Akshan leaves the board in reaction to his play effect, the delayed passive ability "You control it until I leave the board," will not be generated. You will not gain control of the targeted gear even for a moment.