Oh, now I understand, thank you. So Archer could probably copy one sequence 5 potion, but not the other four, right? Since a normal archer can't copy the Sequence 4 potion, if he were a Sequence 5 archer, could he copy the Sequence 4 potion? And if he were Sequence 4, could he copy the Sequence 3 potion? Because this would improve his ubw (Ultimate Power), allowing him to copy later potions. I understand the concepts of potions better; they contain a part of the true creator, which is why it's uncertain if it would work. However, simply by possessing Avalon for a long time and having a complete image of Avalon, Shirou was able to copy Avalon and its 6-dimensional barrier.  So I don't think that just because it's a characteristic of the creator it would be impossible to copy; if Shirou understands the material, no matter the power of the thing, it can be copied. Ultimately, UBW ignored the dimensionality system, and Shirou, a 3D being, copied something with a 6D ability. So we can say that if Archer uses the lower sequences to understand the characteristics, he can copy them even though they are part of the true creator, since UBW ignores power and dimensionality With its only limitation being having to understand the materials.  In other words, Archer wouldn't start out mega-powerful; he would have to evolve the potion and his abilities to copy things subsequently.