Instant kill

Your are with a instant kill ability to kill anything by just a though and one You and your class mate get summoned to fantasy world to defeat the demon king your instant kill ability is the most powerful ability in existence and the ability can be taken away and you're the most handsome being in existence. and your instant kill ability can kill anything nothing can resist your instant kill ability and you can use it in any world any place and once you become 20 you will become immortal in this world they are systems that determines someone power and stats and level determines the person's power and the way to increase someones level is by killing monsters and the name of your instant kill ability is death void