Aryel, Knight of Windgrace

Text:

Vigilance
, : Create a 2/2 white Knight creature token with vigilance.
, , Tap X untapped Knights you control: Destroy target creature with power X or less.

Rulings:

• 4/27/2018 Tapping Aryel to activate either of its abilities while it’s attacking doesn’t remove it from combat.
• 4/27/2018 You can tap any untapped Knights you control, including ones you haven’t controlled continuously since the beginning of your most recent turn, to pay the cost of Aryel’s last ability. However, you must have controlled Aryel continuously since the beginning of your most recent turn in order to use either of its activated abilities.
• 4/27/2018 Once you announce that you’re activating Aryel’s last ability, no player may take other actions until the ability’s been paid for. Notably, players can’t try to make the value of X invalid by removing or tapping your Knights.
• 4/27/2018 If the target creature’s power is greater than X as Aryel’s last ability tries to resolve, the ability doesn’t resolve. You can’t tap extra Knights once the ability has been activated.