23 Jul 2021
You choose which player or planeswalker the Dragon is attacking as you put it onto the battlefield. It doesn't have to be the same player or planeswalker Minion of the Mighty is attacking.
23 Jul 2021
The creature card is already tapped and attacking as it's put onto the battlefield. Any abilities that trigger whenever a creature becomes tapped or whenever a creature attacks won't trigger.
23 Jul 2021
A Dragon creature card is a creature card with the creature type Dragon, not necessarily a creature card with the word “Dragon” in its name.