Light Yagami, perfect student

Hexproof
{4}{w/u}, {t}: Gain control of target creature until
end of turn, you may spend mana as though it
were mana of any color to activate abilities of that
creature.
{3}{u/b}, {t}: Gain control of target creature, it
cannot attack and at the beginning of the next
end step, it dies. Light Yagami loses hexproof
until end of turn.