Grimoire of True Names

All creatures are demon in addition to their
other types.
{t}: All demon creatures gain -6/-6 until end of
turn. Target opponent gains control of Grimoire
of True Names at the end of your turn.
{t}: Pay X life, target creature gets a +1/+1
counter equal to the number of life spent for X.
{2}: You lose 5 life, then name a demon creature
permanent, you gain control of all permanents
with that name on the battlefield.