A character who is the diametric antithesis of Spock, a half-vulcan half-human hybrid who chooses emotion over logic. Suppose, just suppose after rejecting logic, Spock's half-brother Sybok would have traveled to Earth where he met and married an earthwoman and allows his son to be raised on Earth by his mother and to have human emotions. The new character we shall call...Sponn, Spock's nephew. Sponn highly values his human heritage and is highly disapproving of vulcan logic which he regards almost as a curse. He is antagonistic torwards his uncle yet knows him to be an individual of high honor and integrity which leads him to be conflicted and argumenitive at times with his uncle. He is a brilliant starfleet officer in the engineering branch and his personal hero is Montgomery Scott. He is about 70 in earth years but appears to be 30ish having never been in any relationship with any Earthwoman and is a lifelong, so far, bachelor. Sponn's mother was former Starship Enterprise communications officer Lt. Palmer. Since Sponn does not suppress emotion he has never been troubled by the effects of ponn-farr.
Your idea might be an interesting variation of the theme, but we've already pretty much had the antithesis of Spock in Data.