In the case of this game, [Delta] is almost certainly meaning Gene-Deletion, Philosophical Determinacy, or maybe the Uncertainty Principle rather than the number 4. Despite having nothing to do with Kojima anymore, it's really the most Kojima-esque name they couldve chosen
It's a somewhat odd title in my opinion. It most likely refers to the fight between Rockman and Forte. However, since Forte is first introduced in this title and is portrayed as an ally for a majority of the game, calling their battle(s) in the fortress stages 'fate' or 'destiny' seems like a...