What is the work?[]
Most already know the plot of Paper Mario: The Origami King, and goes without saying that King Olly's plan on making everything into origami beings under his control and eradicating the Toads out of anger over the Origami Craftsman. So, moving on.
Who is he?[]
A pair of literal scissors that was brought to life by King Olly and served under the Legion of Stationery. In the game, he slices his way through Bowser's groups leaving them in a position where they existed as fully-ware shreds. He also does the same to Bowser Junior, but he gets better.
Why doesn't he count?[]
Mainly, I don't think he is actually played seriously enough. The game is actually more comedic and lighter and softer in comparison to the ones where Shadow Queen and Dimentio take center stage. Because this is a G-rated game, the idea of whether or not the game itself paints Scissors as being serious enough is to be scrutinized. From all intents and purposes, Scissors, to me, does not come across as being taken as serious.
Namely those people that he cut up are literally made of paper; it lacks the sense of urgency. Especially since his actions are not permanent or irreversible.
Conclusion[]
Ultimately, not basing this on heinousness since you're comparing nigh godlike beings to a literal pair of scissors, but I don't think the game treats his actions that seriously.