He was taking the same pills that Klopp forced him to take in the first season (the first time line)
Remember klopp in the first season he himself invested in the company that produced those pills, in this time line (2nd season) Klopp has no idea about those pills existence while Aeroc looked for them and took them willingly in order to become an omega this is why Klopp found him in the slums.
It just happen as far as I remember based on the novel. He wake up one day that he became an omega along with his memories of the first life. (This will be discussed sooner too, when Kloff ask him about it)
As for the slums, I believe he went there because that is the only way for him to buy a suppressants. Since hes hiding that he became an omega, then asking one of his servants is a no no. Buying them himself too in local pharmacy is a no, too (He dont have a partner to use as an excuse). I think the butler knows hes an omega too, but Im not sure why he cant just ask him to do it instead lols
The butler doesn’t know, but he will in the next few chapters after Aeroc tells him. Oh boy this will be a funny redemption arc for our ML because the butler will be a total cock blocker hahaha. He will act like a strict father who isn’t approved of Kloft marrying his omega son. Hahaha
Aeroc's changed into an omega just recently after he met Klopp and yes the pills he bought from the slums were suppressants, the butler doesn't know yet and will discover it later when Aeroc tells him.
Redemption arc? There's literally NO redemption arc. What he did can never be redeemed for.
Kloff*
There will be an arc, a third season where Klopp will wake up in another timeline but this time he is the one keeping his memories from he's first life and he will suffer a lot to the point that he thinks he is in hell for what he did to Aerocc, this second time line is actually very sweet and it is for Aerocc to find his happy ending with the man he loves after all that suffering, this Klopp has nothing to do with the first one, and let's be honest in the first time line they were both in the wrong, I'm not justifying what Klopp did but Aerocc actions also helped things go the way they did.
Well you are right, but this klopp version will really try hard.
How in the world he become omega again?