"It wasn't who you saw on the platform but who you didn't see..." Thanatos is relieved that someone dangerous isn't after Ryo, but it's not hard for Thanatos to wonder if Zagreus's appearance influenced Ryo's thinking. Did Thanatos influence the train somehow? He had only wanted to go home, to save his world from certain collapse. He wanted to help Zagreus continue on his quest not see him again. It's not the same as what Ryo wants.

"Sometimes, the Fates are unkind. No matter how much you yell or beg, the people you need won't show." And then paths cross differently. It doesn't stop the earlier pain.

"What do you need?" Besides them?