The mismatched timeline with which the Jujutsu Kaisen anime is choosing to tell its story was a risk that is only continuing to pay off. After the runaway success of the movie 0, Season 2 has shed more light on Geto Suguru, the prequel's charismatic and powerful main villain. As the first to focus entirely on him, Episode 5 bridges the gap between the personable version of Geto viewers of Season 2 have become accustomed to and the ruthless villain that attempted to murder several of the series' fan-favorite characters. It turns out, Geto was always on an extremely slippery slope.
Source:https://www.cbr.com/jjk-s2-suguru-geto-evil-cursed-technique-backstory/