kinda both. a villain AND a stalking horse for the price of one lol.
he's charmingly two-faced and sneaky af. he's definitely working against Tarkan but he doesn't seem all that dedicated to his mother or sisters. he often just flatters and reassures them when they're hysterical then moves with his own personal goals in mind.
but then he meets Aristine - who doesn't know who Hamir is, mistaking him for a gigolo/gold digger when he approaches her lmao. Aristine ends up considering him a friend. his morbid curiosity kept increasing when Aristine always seemed to subvert his expectations and he alternates between secretly giving her a helping hand and doing nothing as his mother schemes against Aristine, just because he thinks it would be amusing to see how she reacts.
the last couple of chapters i read though seems to cement him as a 2nd ML when he genuinely felt alarmed, thinking Aristine was in danger and he acted before he could think. he was absolutely petrified when Aristine cut him off (after a series of events & discovering who he was) and he was also confused why he felt that way. his inner monologue seems to point down the "If I can't have her, then no one can" path.
lol kind of. to be clear, the parts i've read doesn't really point to him going extreme-yandere mode, harming Aristine and being crazy enough to make a careless attempt to steal her away. he's still very calculated in his choices and just inwardly confused about his 'missteps' when it comes to Aristine.
like, from a non-emotionally stunted perspective it's obviously a friendship-turned-crush. i remember the part when Hamil tried to beg for Aristine's friendship once again and he was coldly rejected; metaphorically he described it as a closed door he could only gently knock on, whereas before he would either leave the door alone out of disinterest or break it and force his way in. but somehow with Aristine he could do neither.
like, it's my own speculation that if we're talking yandere he would probably be the type to put Ari on a pedestal unharmed while destroying Tarkan just to get to her.
Is 1st Prince Hamir a villain or 2nd ML?