since the start, it was hinted at ch 5, where mc mentioned that he has chip planted on his body (the part where it was his last training day), and then at ch 6, when they met ml, ml ask whether mc is a beta, and the person who comes with mc said, even if mc is an omega, the chip they're using nowadays prevent the pheromones leak, from that conversation i think we can connect the dots.

When did MC manifest as Omega? I thought he is a beta. What happened? Someone tell me which chapter ?