I'm currently reading 'His not my shadow guard, his my lover' and recall a novel with the same troop. It's not transmition. It's a full pledge ancient China BL novel with a twist. It's omegaverse. I only read few chapters, I tried reading it in raws but I gave it up, cause it made me dizzy and totally can't understand 60% of the chapter. So, our mc is a prince. He is actually an omega who was taking supressant since he was child in order to be a qualified candidate or something. The first scene is... Mc is out of imperial palace for a business trip. He went to negotiate for something, but as luck went flying out of his body...at night he suddenly felt symptoms of his estrus. Turns out the supressant he was taking since he was a kid, made his body immune to it. No supressant can no longer stop his estrus. Fortunately or unfortunately, ml was there and he was an alpha. He made ex with his master and made a temporary mark. When mc is going back, his heat is unpredictable and he needed ml alot.