Memnarch, Mirrodin's Soul

Eminence...
{T}: Target artifact becomes an artifact creature
with base power and toughness equal to its
converted mana cost until end of turn.
Whenever an artifact enters the battlefield under
your control, you may pay {X}. If you do, gain
control of target nonland permanent with
converted mana cost X or less until end of turn.
It gains haste until end of turn.