I looked it up and saw some of that idea being called fan theories, backed up by “if he could warg-affect hodor, and that was breaking some warg laws, then he was repeatedly breaking them and could obviously time travel” which got fan theoried into him being the source of the mad King AND Bran is actually the night king.

Honestly, I just attribute a lot of that to bad directing near the end of the show. It was already falling off for a long time by then, and it was unclear and you had to kind of presume what was happening off screen and what capabilities were.