So the seme has his red flags but he is no where near as toxic or frustrating as the guy from kiss me liar. He never says that omegas should be subservient, and he doesn't seek out omegas to please him. He does get forced to go to a dominant Alpha party by his brother, but he mainly dislikes omegas because of their attachment to him. I am going to spoil a little, so continue at your own discretion.
He does get some character development, as he gets scared that Pete was conceived from him forcing himself on the uke. It is kinda meh though, like there isn't much of a chasing arc, and he does lash out here and there. What's coming up soon is that he kicks one of the bodyguards out of the helicopter, as it would have caused him a few seconds of inconvenience (explained in the novel), and uke gets frustrated with him and they have a physical altercation where uke hits him first. There are some explanations for his behaviour, such as him being terrified of his brother, but overall, it's slightly bland. He's not a redflag in the sense that he cheats or rapes uke (in the novel), but like he tries to kill the uke twice at the start of the novel, and not only does he not apologise for these incidents, it's just never really fleshed out. It is important to state that he mainly lashes out because he's mentally disturbed, and not sadistic like Keith.
I hope this helps a little.
I Didn't like kiss me liar at all so im skeptical About this. Those who read the novel please tell me if the ML gets or worse or does he get some character development? Red flags aint my thing at all