Cards: Ashiok, Dream Render, Goblin Engineer

A: If an effect says ‘You may search your library . . . If you do, shuffle your library’ or ‘You may search your library . . . then shuffle your library,’ your opponents can’t choose to search, so they won’t shuffle. So, No, AP may not choose to search, so AP can’t shuffle when Goblin Engineer’s ability resolves.
Approved by Scott Marshall

Cards: Containment Priest, Show and Tell, Heliod, God of the Sun

A: “If a noncreature card wasn’t cast and is entering the battlefield as a creature (due to an effect such as that of March of the Machines), it will be exiled. Similarly, if a creature card wasn’t cast and is entering the battlefield as a noncreature permanent (for example, Heliod, God of the Sun with insufficient devotion), it won’t be exiled.”

We look ahead to see what Heliod would look like when it’s on the battlefield to determine what it’s entering as (thanks to 614.12). If your devotion to white is not high enough, then Heliod is not entering as a creature, and thus the Priest won’t apply to it entering, so Heliod will enter the battlefield and will not be exiled.

Approved by Nathan Long

Cards: Animation Module, Torpor Orb, Walking Ballista

A: Yes, Animation Module will trigger off of the Ballista entering the battlefield, and the Orb won’t stop it. The Ballista entering the battlefield isn’t the relevant part here. It’s that, because of 122.6, entering the battlefield with a counter counts as putting a counter on that object. Putting the counter on as it enters is what the Module is triggering off of, not the Ballista entering, so the Orb won’t prevent the Module’s ability from triggering.

“122.6. Some spells and abilities refer to counters being put on an object. This refers to putting counters on that object while it’s on the battlefield and also to an object that’s given counters as it enters the battlefield.”

Approved by Nathan Long