Mat, Prince of Ravens

Mat, Prince of Ravens cannot be targeted except by equipment.
At the beginning of your pre-combat main phase,
you may call heads or tails and then flip a coin.

If Heads, target permanent gains protection from artifacts, and enchantments until end of turn. If Tails, target nonland permanent phases out until end of turn. If you correctly called Heads or Tails, you
may repeat this process.