Mark and characters are semantically related. in written symbol topic. In some cases you can use "Mark" instead the word "Characters" as a noun or a verb.
Granted this is a bit of a subversion, as most of the characters that are killed are important and do leave a mark on the series even after their death, sprinkling in the occasional Red Shirt here and there (and even a couple of those end up leaving a mark of some kind).
Gundam characters will on occasion use this style, and it's usually a mark of extreme skill on the part of the pilot, since the MS's are usually designed to wield their swords normally.
Mark Hamill was specifically chosen to play the mentor to the main characters of Kingdom Hearts: Birth by Sleep, just as Obi Wan was the mentor to his other character, Luke Skywalker.