We all know that it's just plain wrong for the Gray Raven commandant to suffer forever. And unfortunately that means the game will one day be over. So...WHY NOT MAKE IT GO OUT WITH A BANG!? At the last dialogue, right before the final battle, make it so what you say will drastically alter how the lore ends.
Any ideas on how you think the game should end?
. The main story doesn't necessarily have to end for branched endings to be possible. Kuro can just make gamemode like cursed wave or RDF and add choices there without interfering with main timeline