The three Unforgivable Curses are the Cruciatus Curse, which causes unbearable pain, the Imperius Curse, which allows the user to control the actions of the victim, and the Killing Curse, which causes instant death.
Unforgivable Curses are the three most powerful and sinister spells known to the wizarding world, and are tools of the Dark Arts. They were first classified as "Unforgivable" in 1717. They are the Killing Curse, Avada Kedavra, the Cruciatus Curse, Crucio, and the Imperius Curse, Imperio.
The Shield Charm (Protego) was a charm that protected the caster with an invisible shield that reflected spells and blocks physical entities.
This spell (incantation unknown), which produced a powerful bluish-white bolt, could be used to break large magical protections such as Protego horribilis.
Revulsion JinxThe spell used may have been a non-verbal form of the Revulsion Jinx. In the film version Harry Potter and the Deathly Hallows: Part 2, it was Hermione Granger who used this jinx to free the dragon guarding the high-security vaults in Gringotts Banks during the 1998 Break-in of Gringotts Wizarding Bank.
They started with a wide circle digging down to about six feet. Then they lowered ladders, and bricked up the walls. Leaving a small shelf around the bottom of this layer, they then dug a smaller hole down another six feet, lowered the ladder, and bricked up that layer. They continued this until they hit water.
It was covered with a cap of wood, stone, or concrete. Since it is so difficult to dig beneath the ground water table, dug wells are not very deep. Typically, they are only 10 to 30 feet deep. Being so shallow, dug wells have the highest risk of becoming contaminated.