kuon's personality

is Ren his true personality or is he just acting

I think that Kuon became Ren when his best friend died. His vow to avoid violence with others, and his way of smiling instead of being angry suggests that he is ashamed of his previous behaviour.
Kuon aged ten was how Kyoko played Kuon, but since then he grew up. Also, his father obviously thinks the world of him, so of course he uses the words cute and such.

I think that both Ren and Kuon are the same person, but he likes Ren and hates Kuon.

I know that Ren and Kuon are the same person and Ren is Kuon's stage name, the question i am asking is what is Kuon's or Ren's true personality- that doesn't seem to be clear in the manga

Ren is a persona Kuon created, so that is kind of acting and kuon that his father described is pro-teenage years. and kuon that Kyoko think is another act of Kuon because he wanted her to believe him as a fairy [prince. At last kuon that is so scary is the dark side of kuon, which everyone has. Its just kuon's reason to hold that dark side was broken (he was often compared by industry people with his parents even though he loves his parents, he was bullied because he was half or should I say quarter, so he didn't feel he belonged any where, plus his parents were very busy to support and by the time they realised it was too late) We all go through similar kind of situation but we are able to hold back because that something is not broken. SO, kuon is like most human beings, loves his parents, is very kind, loves acting but he has probably some physiological problem due to bulling trauma he suffered, so to protect himself he turned violent and later to protect himself he turned to become ten.

you could say that kuon/ren's real personality is the one he carries in his head. Neither sickenly sweet, like "Tsuruga Ren" is, nor the dark and troubled and yes, sadistic personality of his teenage years, "Kuon".
His real personality, is the one we see, which is somewhere in between. Sweet, forgiving, troubled, a little sadistic, serious about his work, light-hearted in his play, nature loving, strangely un-arrogant despite his good looks, and a bit of a dork sometimes.

thank you @rose, your response answered my question

Ren made his own vertion/characterization of "Katsuki", the protagonist of Dark Moon, inspired by his own truth feelings and personality. His real self is Kuon, but I think even if Tsuruga Ren is a character, as the readers, we know his thoughts and can see the real him behind the mask. He is: smart, passionate, sweet, vital, talented, generous, playful, pessimistic, observant, wary, strict, meticulous, workaholic, sensitive, resentful, independent, tends to feel guilty, extremelly reserved, cunning, athletic, sensual, he's confident about his acting but insecure about everything else, he lies a lot to hide his feelings and doesn't know how to accept help, he loves nature and animals, he has a childish side and a sneaky humor. In a few words: he's a very complex, interesting, and tormented man.