Transmutation
Chronicles — common
Instant
Transmutation rulings:
2013-04-15: Effects that switch power and toughness apply after all other effects that change power and/or toughness, regardless of which effect was created first.
2013-04-15: Switching a creature’s power and toughness twice (or any even number of times) effectively returns the creature to the power and toughness it had before any switches.
2005-11-01: Note that the wording “Effects that alter the creature’s power alter its toughness instead, and vice versa, this turn” has been removed.