Bode killshot was a mistake
I understand the logic from a lot of people who really like that Cal uses the blaster he got from Bode to kill him, and that you can interpret the second shot as a mercy killing or a sign that Cal is battling his inner demons.
But thematically I think it would have had far more impact if Cal rejected the blaster he was given by Bode because it now represents another step on the slippery slope to becoming him. Bode presents us with his thoughts on Jedi traditions, encouraging us to break from them, and the blaster is the clearest representation of that. Rejecting it could have shown Cal walking right up to the edge, and stepping back down. It would be far more impactful to see how the blaster ultimately fails Bode and shows Cal what relying on it will get him as well even beyond the slide to the dark side.
The cutscenes throughout the game already rely on the blaster too much in my opinion, and this would have been a nice change even without the thematic elements. The fact Cal becomes reliant on it and watches the person who gave it to him show his true colours AND ultimately lose because the blaster broke would be a good moment of reflection. I also feel like it would have finally given us a more satisfying boss ending, as most are either a bit of luck or using the blaster. Decisively cutting Bode down would have been visually more impressive.
In a revised version of the ending we could see Bode almost killing his daughter with the blaster by accident (Jedi don't use blasters because you can't take it back once you've fired and it's too easy to kill with one, this would be a good reminder of that) and then later the blaster breaks as it does normally. Cal instead looks at his blaster in disgust and throws it aside. Bode either tries to rush him or force grabs the blaster so Cal has to cut him down with a single decisive blow (sliced in half, impaled or beheaded preferably, not even necessarily gory so that's a non-issue). This way he rejects the blaster, symbolically throwing away the temptation and recognising that it was taking him down a dark path. And we get a more epic killing blow, it's Star Wars the lightsabers are the best bit.
Alternatively they could keep the ending almost exactly the same but Cal throws his blaster on the ground or towards Bode's corpse in disgust because he sees what it represents and the philosophy that led them both here. He realistically wouldn't want it anymore and his talk with Merrin about resisting the dark side on the way in sort of clashes with how calm and chill they are during the actual fight.
Tl;dr It would have been a stronger narrative moment if Cal threw away the blaster during or immediately after the fight because it represents the philosophy that led Bode to this point and Cal doesn't want to end up like him.