While i doubt we'll ever get an answer for this (like for many other things, sadly), if the "silver-knifed vampire hunter" thing ever happens to become canon, it makes me wonder how really strong Remilia is. To defeat someone that can just stop the freaking time and kill her in a instant, Remilia must be indestructible, or incredibly powerful and capable of warping fate at least to the extent of "not losing" against someone with Sakuya's abilities.
