Reality Stone

When the Reality Stone enters the battlefield, the player is considered invisible by the rest of the classroom for the duration of 1 minute. While invisible, no one can act upon any changes they
do unless the effect is obvious after the minute
has occured.
"The Aether. First, it's not a stone; someone called
it a stone before. It's more of a... an angry sludge sort
of thing, so someone's gonna need to amend that."
—Thor