You miss 100% of the shots you don't take. Even though there's only a 1-5% probability of scroring.
Short answer: It's the name of the protagonist of one of our favourite manga and the name of one of our favourite anime opening.
Long answer: "Killy" is the name of the protagonist of the manga BLAME! by Tsutomu NIHEI. We had thought at first to take the name "Toha", an company in the BLAME! universe, but it was a little too obvious a homage. "Killy" (killy killy JOKER to be more precise) by Kanon Wakeshima is also the name of the opening of the anime selector infected WIXOSS.