12 Most Deadly Spells In The Harry Potter Universe

2. Sectumsempra

While there's always been a movement to forgive Severus Snape of his sins, it's a little hard not to believe that SOMETHING was fundamentally wrong with his moral compass, given the fact that he invents the Sectumsempra hex.

Conceived as a means to defend himself against bullies (and used enough to become one of his signatures) the hex is a particularly brutal means to incapacitate and kill your target. Because, grimly, it's not an instant death.

The curse instead lacerates the victim and they haemorrhage. Even a glancing blow - like the one that hits George Weasley in The Deathly Hallows - is enough to make the wound impossible to heal by magical means.