[@Keksalot] It can be that, if you want. 

It can also simply nullify whatever they inserted in his being that enables such powers. I mean they kind of created these powers, or at least, designed the vessels in a way that they can contain said powers. It isn't far fetched to say that they have the means to disconnect any form of access to the powers they've conferred to these people. 

That or you can also remain in a lead room all day while everyone is partying o;