Trying to figure out how to progress this situation

[g8merc8]

So I've been working on and off on a Mega Man X fan story where X discovers the existence of the original Mega Man and the other robot masters made by Dr. Light, and is trying to figure out what happened to them. There is one part that I've been stuck on for ages that I've had a hard time trying to write. It basically goes like this:

X and Zero find the location of a robot master (I won't say who, but it's not Mega Man) at a power plant and discover that they (the robot master) have been repurposed as the plant's mother computer; their former body is gone. Their memory has been mostly wiped but they know who X is and remember the last time they heard from Mega Man. After some questions, the robot master requests X to retrieve a key but doesn't tell him what it does. They promise to tell him after he gets it.

After X leaves to do this and Zero is forced to stay due to the robot master's distrust of him (they recognize him as Wily's creation and therefore as a potential threat), the computer reveals to Zero that the key will initiate the plant's shutdown sequence and effectively render the entire building inoperative. Additionally, this means that the robot master will die as a result of this. Zero tries to dissuade them, but the robot master has made up their mind. They want to die, they've lived far too long and had enough. Zero realizes that there's no changing their mind.

After this, X returns with the key, and this is the point where I've gotten stuck.

My end goal for this is that I want either X or the robot master to shut the plant down, but it's a matter of getting from point A to point B now, and I can't figure out what should happen in between.

The hard part about this is I don't know how to get X to perform this action, as this is something he would never do willfully, especially considering this is basically a long lost relative that X just found. I also feel like Zero wouldn't interfere with the robot master's wishes after hearing them out, but he wouldn't want to do or say anything he knows will make X upset. It's a very morally conflicting situation and I need suggestions or input as to what I could do here. Any resources you can recommend for stuff like this is also welcome.

[Zelan]

If you feel like this is an action that your character wouldn't do, maybe they shouldn't do it at all.

If you're set on this ending for your story, and you know your character wouldn't do this willfully, you need to figure out what deception would work to make him to it anyway. Maybe the robot master tells X that they will become dangerous if not shut down, or maybe tells X that it will upgrade them somehow (give them a new body, who knows).

How easily X falls for this deception would depend on how much he trusts the robot master as well as how trustful he is in general.

[rook17]

The most interesting dramatic moment you're creating here is the moment in which X is told -- or realizes -- what the robot master's intentions are. Making that moment powerful, and choosing how it happens and how X reacts to it, is the real anchor decision point for the whole rest of the scene. Figure out what you want to do with that moment.

Then, by choosing to have the reader learn the truth before this moment, you're creating an alternative dramatic tension. The 'twist' for X isn't a twist for the reader at that point -- rather, they're actively anticipating whether X will or won't find out it time. Get the mileage you can out of that tension by using the time in between appropriately -- for example, by having X think about why reuniting matters to him, or by having X have second thoughts but still move forward. The gap between what the character knows and what the reader knows creates an interesting tension in those scenes.

At that point, you've built up the moment where the reader knows the two characters are coming together with different intentions and waiting to see how they're reconciled. You have lots of choices you can play with there, but the biggest split to me is between:
(A) X could use the key out of trust or misdirection, and only understand what he's done after the fact. Themes of betrayal, guilt, frustration, but less room for direct conflict.
(B) X could become suspicious, either based on the master's behavior, or Zero's, and confront them and learn the truth in advance. At that point, it's possible that the conflict either centers on the X vs Zero or X vs the master, depending on whose behavior he felt most disappointed by. Either way, (B1) X could eventually be convinced, begrudgingly, (B2) Zero could decide to use the key to end the discussion, or (B3) the master could use the key.

Really any of those four paths could work. You seem least comfortable with B1, which is fine! But figure out which of those stories you want to write and what you think fits the intentions and temperaments of the characters and you'll get there.

[g8merc8]

At that point, you've built up the moment where the reader knows the two characters are coming together with different intentions and waiting to see how they're reconciled. You have lots of choices you can play with there, but the biggest split to me is between:
(A) X could use the key out of trust or misdirection, and only understand what he's done after the fact. Themes of betrayal, guilt, frustration, but less room for direct conflict.
(B) X could become suspicious, either based on the master's behavior, or Zero's, and confront them and learn the truth in advance. At that point, it's possible that the conflict either centers on the X vs Zero or X vs the master, depending on whose behavior he felt most disappointed by. Either way, (B1) X could eventually be convinced, begrudgingly, (B2) Zero could decide to use the key to end the discussion, or (B3) the master could use the key.

Really any of those four paths could work. You seem least comfortable with B1, which is fine! But figure out which of those stories you want to write and what you think fits the intentions and temperaments of the characters and you'll get there.

I really appreciate all the suggestions you're giving me as it gives me some more ideas to play with for the narrative. I think I'm leaning more towards A in this case, since I want to stay away from direct conflict between these characters. Now it's just a matter of writing the scene in a way that would make the reader's heart sink