Premise - like how Loop was another Siffrin, we have another characters, they serve the same guide function as Loop but for The King - being the King from the prologue.
This new character is my concept of the Colour Knight. their colour and armor being a byproduct of a wish-craft born body formed by their wish being broken when Loop destroyed their timeline by their wish to get out.
The Colour knight advises this AUs King, and can remember through loops since they arn't from this version of the universe, so they give The King a different script each act - including a pacifist end to act 3 without a betrayal.
The Colour Knight is a secret Boss - giving The Flower to act 3 King before giving up the fight acts as the trigger for act 6 fight, with an additional requirement of of not getting 2 hats but still leaving The house.
The Colour Knight would have refrozen The House during act 6, and the 3rd floor would resemble Start Again(a prologue)'s version of that floor.
The Colour Knight is a duel type - Scissor/Rock(scissors is because of their blade, rock is their original type from when they were The King.