Stone of Inverted Principles

{t}: Flip a coin. If you win the flip, add one
mana of any color to your mana pool and target
opponent draws a card. If you don't, draw a card,
and target opponent adds one mana of any color
to their mana pool.
Wait, no, this is all wrong. If you add the Barrin's
Law of Intermana Transmutation....no! This is all
wrong!