When Barrin enters, return up to one other target creature or planeswalker to its owner's hand.
At the beginning of your end step, if a permanent was put into your hand from the battlefield this turn, draw a card.
"There is no age at which you stop learning."
(23/06/2020)
Barrin's last ability checks the entire turn, even before Barrin was on the battlefield.
(23/06/2020)
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.
(23/06/2020)
If a token is returned to your hand, it's put there before it ceases to exist.
(23/06/2020)
The permanent that was returned to your hand doesn't have to still be there.
(23/06/2020)
You draw only one card, no matter how many permanents were put into your hand from the battlefield during that turn.
