I’ve seen some romhacks made based on ChatGPT’s input, and it did have some interesting ideas for gimmicks but the enemies turned out somewhat overtuned. It’s promising to see that there’s progress in AI actually implementing things.
If the intention is to make it usable by a larger crowd in the present, making it compatible with FEBuilder would be ideal. This doesn’t mean much, since FEBuilder can read buildfile romhacks just fine. It might struggle if you obfuscated pointers or did some complex changes to the engine, but this is the kind of thing you wouldn’t do in FEBuilder anyway and would be supposedly skilled enough to handle yourself by that point. I’m not sure exactly what makes it hard to work with, but if the pointers are where FEBuilder expects them to be, I think it’d be fine for the usual things like chapters, units, classes, etc.
Now, as much as I’d prefer to see it be a romhack, if you’re looking at the future then compatibility with Lex Talionis is probably better in the long run, since that is also getting updated. Another important fact is not being limited by the GBA restrictions. You could make map generation be outsourced to some image generation AI, since maps in LT are images not constrained by tilesets, or some music generation AI for BGM, since we wouldn’t be limited by the GBA soundfont (or whatever’s the best term for it, I’m not a musician), for example.
I understand that you already went the LT route, just thought to point those factors out anyway.
As for how it works, if it could be made modular, that would be a ideal. I guess that’d be a mix of 2 and 3.
Specifically in my case, I usually had a clear gimmick I want to implement. But I also need a map and units to make that gimmick playable, and it helps to have some cutscenes as well. So I would use it for those 3 things, and then make events myself. If I’m impressed enough by the events the tool makes, perhaps I’d consider leaving those to it as well, but the bar would be higher since events are what I enjoy the most. Since my chapters tend to be event-heavy, I’d probably do one chapter at a time until I’ve tested it enough.
But, on occasion, I also think “it would be cool if there was a romhack based on this setting, but I don’t have any other ideas for it”, and that’s where I’d give it a description of the setting and let it do everything else for multiple chapters. Maybe then I’d get inspired to add in some events to it.
As for some generation suggestions, the topic What historical events would be well-suited for a Fire Emblem game? has some good ideas that you could put as a prompt. If I may suggest one: “A romhack centered on Oda Nobunaga’s unification of the Oda clan after the death of his father and the succession disputes that followed.” It’s a simple prompt, but since there’s historical background you could specify which conflicts or add more details if needed.