Ralsei needed the gift more than anyone.

Susie is kind of caught off-guard and immediately assumes Kris stole the gift.

Noelle just becomes confused and starts to overthink why Kris would ever give her a gift like that.

Berdly is genuinely flattered and I wouldn't be surprised if giving him the gift comes into player in chapter 5.

Ralsei has never been happier when you gave him the gift. Think about that. He's telling the truth. He has never been shown generosity, he's also given to others. He does not even understand the idea of reciprocation. He is a being of pure selfless compassion. And you give him a gift. Would you not be speechless yourself if you were in that position?

When you give the gift to Ralsei, what do you say to him?

"You are worthy of generosity. You are a real person to me. To give to you makes me just as happy as when you give to me, and I see you as a friend and a person. Your presence transcends the barrier between Lightners and Darkners to me."

You see it in chapter 4, he sleeps with the plush every night, not because it's soft, or it looks like him, but because it's the most solid and concrete evidence of his personhood. From Ralsei's perspective, to receive the gift is a monumental act of love and validation. There is no better recipient.