Answer:
There are avada kedavra, Curcio imperio
Curcio a torture curse when used its victim feels the most painful experience imaginable. no counter curse.
imperio: when used the attacker can control the victims body to do anything really anything the way to stop it is to fight back and force yourself to not do it.
avada kedavra: this is the worst of the worst its the killing curse. when used a jet of green light flashes from the attackers wand and the first person it hits dies before even closing their eyes.