Plot Armor Breaker
A character who kills another character that has been shown to have Plot Armor in the past.
What's that? The author has given Awesome McCoolname the mystical Plot Armor? No one has been able to truly kill him? Tell that to my friend here. They may have been shown having power close to none when compared to their opponent, but, when the right moment comes, they gain an immense power boost and either end up killing Mr. Plot Armor in a stunningly beautiful fight or delivering a swift death to them. Different from Defeating the Undefeatable, in that the defeated character has been shown to dodge death in ways that seem as if the plot calls for it.
Hello, Unknown Troper. You'll need to get known to lend a hand here.