honestly I read the creator note and even though the author didn’t give much detail on Guwon & when their coming back i do have some theories. Like I think Guwon is perhaps 32 or 34. And for his height the author didn’t give much all they said was “Anywhere from two meters to two centimeters… Totally up to you!” So maybe he indeed is two meters (feet: 6’6) (cm: 200).