Cultist Ritual

{b}{b}: Target sorcerer or wizard gains a darkness counter. Creatures with darkness counters have
+2/+2 and gain hexproof. If you have at least 3 creatures with darkness counters on the battlefield, untap all lands you control at the beginning of each end step. When this
enchantment leaves the battlefield, exile all
creatures with darkness counters on them.
The Ancient One: "Master Kaecilius. That ritual
will bring you only sorrow."