WARNING: The following contains major spoilers for Season 3 of Cobra Kai, streaming now on Netflix.
Cobra Kai has fiddled with its young male leads over the three seasons thus far, especially Tanner Buchanan's Robby. As Johnny's son, fans expected he'd follow his dad's toxic ways, but he ended up being a sweetheart, training under Daniel and Miyagi-Do. It helped that he fell for Sam and that his rival, Miguel, turned into Cobra Kai's arrogant, rash leader for a bit. However, by the end of Season 3, Robby becomes a sympathetic villain, as he feels betrayed by the people he loved and trusted the most.
At the start of this season, Robbie's on the run for injuring Miguel in the West Valley High brawl, stealing a car from Daniel's dealership. However, as Daniel tells Amanda, Robby's a good kid who made a mistake, so there's hope. While Daniel couldn't find Robby, the kid meets his mom, who's recovering in rehab and calls Daniel over. Just when it seems like they're going to reconnect as sensei and student, Daniel shocks Robby by bringing in the cops.
He promises to use his resources to help Robby, but the teen thinks Daniel's a traitor for not even discussing going to a youth detention center with him. It gets worse as Johnny bails on visiting Robby to help Miguel out in the hospital. When Robby finds out, his greatest fear comes up again, which is that he's not good enough, believing Johnny prefers Miguel, who's practically a son to the sensei. In fact, Johnny spends more time with Miguel in recovery than he does with Robby in the detention center.
This makes him more violent in lockdown, especially as he doesn't know how to connect with Sam following the brawl. He believes she sees him as a monster, and when he eventually gets out, he finds her with Miguel, believing she's left him for the other. He was hurt before when Tory said Sam cheated on him last season with Miguel, and while he doubted it at first, seeing them together at the dojo breaks him.
This allows Kreese to slip in as a shoulder to lean on since, in Robby's eyes, everyone under Miyagi's banner are traitors; therefore, Kreese capitalizes on this, as he wants to turn Robby into the warrior Johnny couldn't be. This cumulates with Robby choosing Kreese when the sensi takes on Johnny in a fight.
With Kreese and Tory, Robby thinks he has the family he's always deserved. Kreese is using the gaslighting tactics his commanding officer used on him in Vietnam, so with all this in play, Robby has a false sense of security that's going to push him as a villain to take the trophy back from Miguel by any means necessary.
Cobra Kai stars William Zabka, Ralph Macchio, Courtney Henggeler, Xolo Maridueña, Mary Mouser, Tanner Buchanan, Jacob Bertrand, Gianni Decenzo, Peyton List and Martin Kove. All three seasons are available to stream now on Netflix.