From what we know about him, Nathaniel is an impressionable, foul-mouthed nerdy child. Even after joining Miyagi-Do, he has trouble letting go the Cobra Kai creed of "Strike First. Strike Hard. No Mercy." nor does his training limit his aggression as seen when he fights Bert. However he does show prominent skill in Karate, as shown he was able to overpower and pummel Bert without the need of his glasses to see.
He joins the Cobra Kai Dojo shortly after Cobra Kai's success at the All Valley Karate Tournament. However, after Daniel LaRusso, the sensei of the rival Miyagi-Do Karate Dojo confronts Cobra Kai's sensei Johnny Lawrence about trashing his dojo, Nathaniel likely realizing that Cobra Kai's ruthless teachings have gone to far leaves the dojo along with Chris and a few other Cobra Kai students.
At Moon's party on the last night before the first day of school Nathaniel is shown dancing and the crowd cheers for him. When the cops arrive Nathaniel presumably runs away like the rest.
When the school brawl occurs the next day, Nathaniel fights Cobra Kai student Bert. He gains the upper hand at first. However, after some time Bert is able to break his glasses. An angry Nathaniel then tackles Bert and starts punching him, but a security guard then picks up Nathaniel and takes him and Bert away (possibly to the principles office).
- He loves humor related to mathematics, as revealed in "Pulpo."