Are Nino and Luka actually the same Person? They are both musically talented (DJ and Guitarist). Both are friends with Adrien and crushed on Marinette. Both are reptile superheroes and caring older brothers (but we only found that out in season 3 for some reason). And they are both generally pretty chill, and they only got akumatized because someone else was wronged. I mean, sure we've seen them on screen at the same time, but we've seen Marinette and Ladybug together in Kwami Buster so idk...
I can think of a few problems with this theory
The post that started it all