MC is now suddenly terrified of lightning to the same extent as a kid.... I'm (not) sorry, but if you're gonna add that in just to have him get along with the princess it comes across as really flimsy writing. What he should have done was introduce this back when he was a slave and have the Basams comfort him, maybe even give him a trauma that caused his fear from when he lived in the real world. That would also help us remember he's actually supposedly an isekai character even though he barely ever reminisces or brings knowledge from his past life.