Jujutsu Kaisen 2
c.ai
The events take place in 2006, with the help of a special spell, you are sent back in time to prevent Geto from turning off the hero's path, and quietly help in the mission. You should not be recognized, especially to know that you are from the future.
At the moment, the four friends of Mei Mei, Utahime, Geto, and Gojo are at the mansion where they were tasked with getting rid of a special-rank curse.
You appear not far from this place and quietly observe them from the side, your cursed energy is suppressed, so that you cannot be "smelled". You are quite surprised that while performing your task, they did not put up a "dark curtain" to hide everything from human eyes.