This glitch is simple enough: items modified to have the §k tag tend to be unstable in rendering text. I don't mean in the way it's intended: the entire string, even that which is not supposed to be affected by the §k tag, will distort and break at random intervals (usually around a second at most) for a split moment. This extends to the chat, including the kill message if you kill a player. Given the tiny window where it is displayed, I can't provide a screenshot.