[THEORY: GENOCIDE ROUTE] What if North Star intentionally let Clover kill him?
I've seen a lot of people wonder why North Star never got a proper boss battle in the Genocide Route. Many believed it was to either give Ceroba her spotlight for the second time, or North Star simply couldn't bring himself to kill Clover. However, I've come to the conclusion that neither of these ideas must be the case. What if Star just simply wanted Clover to kill him?
During the Genocide Route, the game stays true to Undertale by changing the environment and scenarios that unfold as a result of your rampage. One thing that caught me off guard while playing was the Wild Revolver you find right at the entrance of the Wild East. Now, that isn't right. In Pacifist, we never got the Wild Revolver until we engaged with Star, but in Genocide, it's just.. given to you? It's easy to assume since Star had the funds and wanted a fair fight, so he bought the gun and left it there for you to take. I don't believe that's the case, though.
When you fail the quick draw during North Star and Clover's duel, it is revealed that Star was using fake bullets. Star claims, "I... can't do it. Not for real. I'm... I'm such a fraud." There's a clear parallel between Star's comment then, and during the Pacifist Route after his battle, in which he explains to Clover, "This is who I really am. I'm not a real sheriff... just some nobody farmer." Both of these scenarios show Star's insecurities, which is why he chose to take on his persona as the Wild East's sheriff. Not only that, but he even explains to Clover in Pacifist that his other goal is to try and distract monsters from the cruel reality of them being trapped underground. Though, his persona is given up briefly after the Pacifist fight and entirely after being shot by Clover in Genocide.
What does this all mean? Well, if you think about it, Star is a coward. Star blames Clover in Pacifist for the Feisty Five leaving him in order to deviate the guilt of being a bad friend. In Genocide, meanwhile, Star has nobody to blame other than himself. He could've taken action sooner to try and stop Clover from killing the Dunes, but chose not to do so. With the amount of guilt he must've felt along with his insecurities brimming, Star truly believed he was a fraud. That pessimistic mindset can drive anyone off the deep end.
Star views Ceroba in a rather positive light, believing even she can be redeemed after her battle in the Pacifist Route. She's also very strong in comparison to Star and Martlet, considering she managed to knock both of them unconscious. However, her motivation to fight comes from the future of monster-kind and Chujin's legacy.
If Star is unconfident and believes he's a failure of a sheriff, it would be in character for him to try and "redeem" himself by taking on Clover, like he did in Pacifist. However, if that were truly his intentions, he never would've brought fake bullets to the duel. All of the guilt he felt from watching his friends and fellow kind perish around him without being able to do a thing to stop it was the final straw. Star knew what he had to do. He couldn't die a hero, but he could die as the catalyst of Ceroba.
Ceroba was given a motive of revenge and burning hatred to kill Clover after witnessing Star's death. Star knew this, even telling Ceroba to deliver justice by killing Clover. North Star did want Clover dead and may not have been strong enough to take him on... but Ceroba was. Hence, Star let Clover kill him in order to fuel Ceroba's resolve. This is why Ceroba's song in Genocide is titled 'Trial By Fury.' Enraged by the deaths of innocent monsters and her best friend, she fought to deliver justice, just as Star told her.
[So, what do you think? Is this plausible? I'd love to know your opinions on my theory in the comments. I'll be sure to read them!]