Captive Rage

Gain control of target creature until end of turn,
untap it.
Until end of turn that creature has haste and rage.
(A creature with rage deals 2x damage to non-blue sources but takes 2x damage from blue sources)
{8}{r}{u} Captive: You may cast this spell for its
captive cost. If you do, perminantly gain control of
that creature instead.