Oath of Armis

When Oath of Armis enters the battlefield, target opponent reveals their hand. You may choose a nonland card from it. That player puts it on top
of their library.
Whenever a creature becomes tapped, if it's
attacking a player or planeswalker, it doesn't
untap during its controller next untap step.
"As I fail. I learn. You will not get rid of me easily. I
will keep watch." *wink*