Nauri of the Bvuscik Clan

When a creature you control taps, you may
choose to keep that creature tapped for the rest
of the game, if you do, all creatures you control
can never tap except for this creature.
{1}{u/b}, {t}: Tapped creatures you control become
5/5 artifact creatures with "When this creature
enters the battlefield, all creatures that are tapped
for the rest of the game untap. This ability can't
be countered."