Myrdin, enigmatic wanderer

At the beginning of each player's upkeep, they gain control of Myrdin, enigmatic wanderer and untap it.
{w}{t}: You and target opponent each gain 3 life
{u}{t}: You and target opponent each draw a card
{b}{t}: You and target opponent each discard a card
{r}{t}: You and target opponent each take 2 damage
{g}{t}: You and target opponent each proliferate
Whenever Myrdin, enigmatic wanderer's owner is targeted by one of its activated abilities, they copy it
and may choose new targets for the copy