Princess and her knight(Overlord AU)

Form what I understand domain expension is basically reflecting your soul on the world using enrgy, and your mind is working as sort of perspective, so one soul can have many domain expension, just like every thing can look different depending on perspective, but still be the same thing, lets say your mind works as your own perspective and representation of your internal domain aka soul (in some interpretation soul i world itself as fragment of reality, or holds one, becouse soul realm) so you can reflect your soul on world basing on your will and understanding of your soul, i mean, you can have different looks of one thing, but you can imagine whole thing, and even its internal part, and understand its every function. Now lets say that your soul is making you yourself, a soul strong enought can generate enrgy and sustain mind on its own without need of material ir ny ither type of body or any kind of energy as sustainment, anchor, or whatever. then everything that is part of you have its influence and relfection on your soul, at least as form of information, memory image reflected on your soul, if not formation and shape of or in soul (look reincarnated as a slime, where skills are basically advenced patterns in soul, generally permament magic circles but in more advenced forms and made of soul) then every part of you is part of the image of your soul, and then EVERY PART OF YOU CAN BE REFLECTED ON WORLD AROUND YOU USING YOUR ENERGY or directly on your enrgy, and become a part of your domain, So he can make it that as long as he have understanding of any of his skills or attributes, and enought will and focus to maintain a clear image of it, he can extend a domain with its characteristic as long as he have enought enrgy, Domain with sukuna cutting abilities, domain with elements like sukuna fire basing on their understanding, domain with constant supression like demon lord haki, domain that overwhelm and overfolw with enrgy like his body and genrates enregy like dragon core, regeneration and defense domain becouse of avalon basically being merged with or atrsched to or residing inside his soul, maybe some dimensional barriers and healing in every doamin as passive effect of every domain becouse of any mechanic you will think of, for exaple throwing more enrgy in avalon would extend its powers, it makes sense as it haves dimensional ability to be able to work on distance, especially if he will have barrier domain, and even if not it would be logical to extend avalon powers to barrier to some extent making it more stable, and maybe impossible to be damaged from one or two sides or even making his domain a space cut off from reality. Even overwritting actual reality space with avalon space would make sense, its your fanfic man, go wild, you have free hand, i am proud to be here to throw ideas at you and see if they help you, It is rare to see as good wor as yours at such early stage, where one can actually help, becouse there are no like 100 useless comments 30 limited after chapter pops up so author have no motivation to read them.