Daoist_KittyKat
Author, just to confirm, do you at least know how strong a 12 dimensional se can be? Keep in mind that no existing being from the DxD and ExE world can harm you in any way, just go to Mister Mxyzptlk from Dc Comics, he is a 5-dimensional being, and the guy can destroy/Create/deform the Dc universe, I tell you, so that you take into account the true scale of power of beings from higher Dimensions
that's why I say he is the strongest. but his Avatar still can be killed because it was an Avatar that had been lowered into a 3D existence in order to interact with the 3D world. For example, if Ainz use something like Reality Slash that ignore the 3D rules, he can harm Ray's avatar body. but even if the avatar is killed. Ray can recreate another avatar and move his counsciousness back there and essentially revived himself.
Morningstars_Hell:Na bro you don't understand 1% infinity is still infinity. Lets take an example of just a 4th Dimensional being, 4D being can see everything, nothing can be hidden in 3D from him. He can take anything from anywhere, he can destroy your heart without even hurting you from outside. Its like looking at a painting, even when there is a line dividing it we can still see both sides. So forget about 12D So if you want to lower mc power to like Peak 3D(universal level), you will have to make mc powers by 9 infinities lesser that his real power and make some power protecting the universe from higher dimensions like how speed force does to dc, it will be like looking at a painting but it is covered by something so we can't see it. Also even in marvel comics there is a system so higher Dimensional being doesn't destroy lower dimensional being i.e. when dormammu or some higher being attack they have to lower them self to 3 Dimension infinitely so he have to attack infinite number of universe at the same time and if even one dr strange from infinite universe defeat him it will be like dormammu getting defeated completely. It even happen when thanos with infinite gems fight love & hate. Love & hate had to fight every thanos in infinite universes.