You draw only one card, no matter how many permanents were put into your hand from the battlefield during that turn.
2020-06-23 • wotc
The permanent that was returned to your hand doesn't have to still be there.
2020-06-23 • wotc
If a token is returned to your hand, it's put there before it ceases to exist.
2020-06-23 • wotc
Barrin's last ability checks the entire turn, even before Barrin was on the battlefield.
2020-06-23 • wotc
If a permanent wasn't put into your hand from the battlefield before your end step begins, Barrin's ability doesn't trigger at all.
2020-06-23 • wotc