I just don't think advcoc is the only way to beat the holy knight, do you think oda will introduce other ways to beat or incapacitate them (since oda doesn't kill).
even though gaban sliced sommers in half, and that didn't kill him. oda could have just have had gaban cut his arm off and still show the readers that you can harm them with advcoc, but not being able to kill sommers even with advcoc means there is something else to the regeneration stuff that we don't know.
even though gaban sliced sommers in half, and that didn't kill him. oda could have just have had gaban cut his arm off and still show the readers that you can harm them with advcoc, but not being able to kill sommers even with advcoc means there is something else to the regeneration stuff that we don't know.