The ability that defines Adeline's power works in all zones, not just the battlefield. As long as Adeline is on the battlefield (and still a creature), that ability will count Adeline itself.
2021-09-24
Attacking with any creatures will cause Adeline's last ability to trigger. Adeline doesn't have to be among them.
2021-09-24
Tokens will be created for each of your opponents, not just opponents that you attacked.
2021-09-24
You choose whether each token is attacking that opponent or a planeswalker they control as those tokens enter the battlefield.
2021-09-24
Although the Human tokens created by the triggered ability are attacking, they were never declared as attacking creatures (for the purposes of abilities that trigger whenever a creature attacks, for example).
Adeline's power is equal to the number of creatures you control.
Whenever you attack, for each opponent, create a 1/1 white Human creature token that's tapped and attacking that player or a planeswalker they control.
