Rulings

• 2018-07-13
  Although the token is attacking, it was never declared as an attacking creature (for the purposes of abilities that trigger whenever a creature attacks, for example).
• 2018-07-13
  You choose which player or planeswalker the token is attacking. It doesn't have to be attacking the same player or planeswalker that Gyrus is attacking.
• 2018-07-13
  Any enters-the-battlefield abilities of the copied creature card will trigger when the token enters the battlefield. Any "as [this creature card] enters the battlefield" or "[this creature card] enters the battlefield with" abilities of the chosen creature card will also work.
• 2018-07-13
  If the copied creature card has in its mana cost, X is considered to be 0.
• 2018-07-13
  Gyrus's token copies exactly what was printed on the original creature card and nothing else. It doesn't copy any effects that modified it before it was put into your graveyard.
• 2018-07-13
  If Gyrus enters the battlefield without being cast, then no mana was spent to cast it. It enters the battlefield without any +1/+1 counters. If no other effects are increasing its toughness at that time, it will be put into its owner's graveyard as a state-based action.
• 2018-07-13
  The amount of mana you spent to cast Gyrus is usually equal to its converted mana cost, normally 3 plus the value chosen for X. However, you also include any additional costs you pay, including the commander tax.
• 2018-07-13
  If another creature enters the battlefield as a copy of Gyrus, consider how much mana was spent to cast that creature to determine how many +1/+1 counters it enters with.