SCP-2317, Eldritch Nightmare

Indestructible, Deathtouch.
SCP-2317, Eldritch Nightmare comes into play with 5 Shackle counters on it, as long as it has a shackle counter on it, it can only use the ability below.
{t} Remove one Shackle counter, SCP-2317, Eldritch Nightmare cannot untap this turn.