Obliviate

Obliviate spell is also known as memory removal spell. It allows removing a specific memory from the target’s memory. It has been usually using by Obliviators to remove Muggle’s memories when they see a wizard’s magic. Obliviate spell used many times along the wizarding history.

If wizard casts it correctly, it has no side effects but when it casts wrong, it can damage the big portion of one’s memory even could kill because of brain damage. Something similar to this situation happened to Gildoroy Lockhart while he was trying to open Chamber of Secrets with Harry Potter and Ron Weasley. He was tried to remove Potter’s memory about Chamber of Secrets but the spell was backfired and caused him to lose his memory. Memory loss caused by Obliviate usually treatable but there are some expectations like Lockhart which memory loss could not treated.

Obliviate spell can lose its effect with torture. In 1994, Lord Voldemort tortured Bertha Jorkins and the spell lose the effect on her. Breaking spell with this causes massive damages on person.