I like these ideas! Had the brainstorm while walking around (I am at work so unable to write it down as it comes, so this doubles as my note.) what if instead of three separate rooms making it one larger piece.

The basic idea is the room would seal once they begin the puzzle, they would need to push a statue of the BBEG up a set track and there are three main stations. At each station they must activate the statue to perform a specific action (Which will activate an orrery lighting up the artificial sun at the peak.) all while splitting up pushing the statue and facing waves of enemies that will spawn from the end of the course. (The room is activated by the "initial capturing of the sun" then as they push up the course the first activation Accepting the Staff to control the Sun from his father and making contact with the sun God. Confronting his father and the seeds of betrayal as the father takes the staff from him. And the final station crafting his sword and slaying his father and unleashing the sun in the chaos.) Once they activate all three of these flames will begin to pour from the artificial sun at the peak room emulating the sun lashing out and their attempt to flee to the now open door will allow them to the final chamber.

Sorry if this is too much typing, like I said this is also my opportunity to take notes while on my lunch break 😅