Mind Stone

If Mind Stone would become untapped while it has
a burden counter, instead remove a burden counter from it.
{t}, {2}, {r}: Gain control of target creature until end
of turn. Untap that creature. It gains haste until end
of turn.
{t}, {7}{r}{r}, Put three burden counters on Mind Stone:
You gain control of target opponent during that player's
next turn. After that turn, that player takes an extra turn.