25 Sept 2020
Because all attackers are declared at the same time, the returned creature can't attack during the same combat it returns, even if it has haste.
25 Sept 2020
If Drana attacks a planeswalker, that planeswalker's controller is the defending player.
25 Sept 2020
The returned creature remains a Vampire in addition to its other types even after Drana leaves the battlefield.
25 Sept 2020
The defending player chooses a card and you put it onto the battlefield all while Drana's ability is resolving. No player may take actions in between those events.