The boss did not respawn after I died and reloaded the save. Outside of that, the moveset was varied and telegraphed and it felt reminiscent of fighting Zero in a Mega Man X game.
Strange issue with the reload? Though, technically I should have disabled save/load all together for this. That being said, I will need to test my save/load system in the broader context of the game to make sure there's no bug.
Of course! I referenced and refactored a lot of your save/load code from the tutorial to set up a room to room autosave for a project I'm working on, it's working pretty well with no bugs so far. Would there be a persistent data entry flag involved with the boss spawn that might be causing it?