Brain elemental

At the start of each players upkeep, they untap
this permanent and take control of it
{1}{t}: draw a card and put the top card of
your library into exile. any player may activate
this ability
Whenever this permanent is tapped, the owner of
Brain elemental decides target creature that
inherits Brain elemental
(to inherit, Target permanent receives the rules-text, colour, and secondary type of Brain elemental)