I had an online ex when i was 13. He was 33 but pretended to be a teenage boy. He confessed to me that he was actually in his 30s and that he still missed his ex who was in his 20s (22-23?) and that it was wrong for him to talk to me at my age (true).
He eventually showed his real face, which i forgot about, on his instagram (which has either been deleted by him or i forgot the username anyway). He then told me it was my fault because i guilt-tripped him into dating me and also “groomed” him, even though i didn’t make him feel bad at all. I liked him and he showed an interest, i thought he was like 14.
Echoing the rest of the comments here: as soon as he knew you were 13, for him to continue dating you is fucked up.
Also for him to blame you for making him date you is absolutely bizarre and stupid. HE decides whom to date.
And now to answer your question: I can only assume he doesn’t feel sorry. I could believe he might feel guilty but that’s because he realizes how fucked up the whole thing is. I can’t say for sure, and I don’t think he really tries to reflect, otherwise he wouldn’t even have gone that far.