Xantha Shadowsoul

{u}: Put a freeze counter on target creature.
Creatures with Freeze counters only untap
during their controller's second main phase.
Activate this ability only as a sorcery.
{2}{b}, {t}: Gain control of all creatures with
freeze counters on them. Untap them. Those
creatures gain haste until end of turn. At the beginning of your endstep, all creatures with
freeze counters return to their owners control.