Itachi, The Scarlet Slayer

Whenever Itachi The Scarlet Slayer becomes
blocked by a creature or becomes targeted by a spell or ability your opponent controls, you may pay {b/r}{b/r}. If you do, choose one of the following. modes -
• Switch target creatures' power and toughness until the end of the turn.
• Counter target spell. You may choose a new target for the spell or ability that your opponent controls.