Polaris' Song

{3}{u}: Tap target creature, It doesn't untap
during its controller's untap step. Activate this
ability only once each turn.
—
"Slumber, watcher, till the spheres
Six and twenty thousand years
Have revolv'd, and I return
To the spot where now I burn...
Only when my round is o'er
Shall the past disturb thy door."
Polaris—H.P.Lovecraft