Well, he always was. But now he's become even more.
Also appreciate how so far there's been zero segs drama. (NBR) Sister? Bang. Mother finds out? Bang both of them. Meet princess? Bang, with the Sister. Claymore challenges MC to segs battle? K turns into a 4some. the master finds out? fivesome.
Seriously, there's so many harem manga out there but almost none of them have actual orgies. Soemtimes MC will bang around, but either with the members unaware, or aware but jealous. It's a strange breath of fresh air.