>>151059895
Felix has been a senti since debut (them having episodes named after sentis like Ladybug, Feast, Gabriel Agreste and Felix) and has been one of the biggest contributors to Adrien is a Senti theories (which might've been planned for Emilie's cause of death since the beginning, since the broken peacock has been with Gabe since season 1)
Kagami was revealed to be a senti in season 5, but they likely planned her to be such in season 4 at the earliest with the rich kids assembly during Gabriel Agreste