Killing With A Sword, Putting To The Sword
noun, verbal noun
A slice kill is a killing with a sword. You don't want to hear this, if at all possible.
ざんさつ
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
僕のお気に入りのアニメキャラクターが斬殺されてしまった。
My favorite anime character was slaughtered.