Smiting

Smiting is an ability inherent in all angels, allowing them to kill anything with a single touch. When angel places their hand on whom ever they wish to smite, the being face becomes consumed with light, leaving their eye-sockets burned out and liquefying their insides. However, Alastair was able to deflect Castiel's attempts to smite him in 4.10 Heaven and Hell and due to Leviathans predating angels, they appeared to be immune as well.

The Host of Heaven is also able to combine their powers into one single focused blast of energy. Smiting of this magnitude has such power that it can cause fallout which will poison the areas for miles from ground zero. This fallout can negatively effect humans that approach ground zero, inducing a smiting sickness, which can lead to death (or in the case of Lot's wife, turn into a pillar of salt). Smiting of this magnitude rarely happens on Earth, with the destruction of Sodom and Gomorrah being the only known mass smiting before the arrival of Amara.

Episodes

4.01 Lazarus Rising

While Sam is staking out Johnny Mac's Diner after Dean's earlier demon confrontation. Sam sneaks into the darkened diner, as he creeps in quietly, he sees the cook from earlier face-down on the floor, his hands bloody. Sam crouches and turns the man over, revealing his eyes burned out and drying blood caked on his cheeks. He soon gets tackled from behind by the demon waitress, they trade blows before Sam eventually shoves her away, revealing that she too has empty, burned out eye sockets and blood trickling down her face.

4.10 Heaven and Hell

When Alastair his demons try to take Anna away, Castiel and Uriel arrive. While Uriel smite the subordinate demons. Castiel attempts to smite Alastair, but is shocked to find he has no effect on the demon.

4.20 The Rapture

As the demon possessed Amelia leaves the room, a demon walks towards Claire, who is tied to a chair and unconscious. The demon picks up a pipe and swings it towards Claire, but she suddenly grabs the pipe in one hand and places the other hand on the demon's forehead. The demon screams as he is killed in a bright light. Using the distraction, Sam and Dean turn on the demons holding them. While they struggle, Claire, who is now possessed by Castiel, burns away the ropes holding her. As Dean is being pummeled by the male demon, Castiel approaches and places her hand on his head, killing the demon.

6.19 Mommy Dearest

To locate Eve, Castiel abducts the vampire Lenore, due to the psychic connection all monsters have with her. After Lenore tells them of Eve's locations, she asks to be killed, telling Sam and Dean that Eve's influence and voice are forcing her to feed on living humans and pleads with Sam and Dean to end her life. Castiel then touches Lenore's head. Light shines out of her eyes and mouth, her face flames and she dies.

6.20 The Man Who Would Be King

To tie up loose ends regarding his partnership with Crowley, Castiel attacks two of Crowley's "hunters," smiting them with ease. As the demon Ellsworth attempts to make his escape, Castiel captures his demon smoke in his hand shoves it back down Ellsworth's throat, and with his hand covering the demons mout smites him.

6.22 The Man Who Knew Too Much

Empowered with the souls of Purgatory, Castiel, and believing to possess the power of God simply snaps his fingers, causing Raphael to explode at a sub-atomic level.

7.17 The Born-Again Identity

After discovering Castiel is an amnesiac named Emmanuel, Dean and Meg attempt to get him to remember who he is by sending him to confront the demons guarding the hospital Sam is staying in. As he walks up to the demons, who stand in shock, having heard Castiel was dead. Castiel lays his hand on the head of the demon standing in front of him and smites him, which causes him to have his memories to flood back. He goes on to smite two more demons simultaneously with a hand to each of their faces. As the last demon attempts to make an escape, Castiel teleports in front of him and tells him he doesn't think running will save him and smites him, having regained his full memory.

8.05 Blood Brother

While in Purgatory, fighting alongside Dean and Benny, Castiel is able to smite an unknown monster with his angelic touch. Pondering afterward what happens when you kill a monster in "monster heaven"?

8.07 A Little Slice of Kevin

While looking for Kevin, Castiel and Dean walk through the factory. Dean turns to find a demon behind him, as he attempts to kill the demon, he is sent flying into backwards. As the demon turns his attention to Castiel, Cas begins to takes a couple of steps backwards before placing a hand on the demon's head and smiting him.

9.06 Heaven Can't Wait

A suicidal man by the name of Joe is found by the Riet Zien Ephraim, who feeling Joe's pain, attempts to relive his pain by smiting him. Ephraim later pays a visit to a high school where he finds a heart broken teenage girl, who had just been broken up with. Seeing her crying, Ephraim does the only thing he can think to stop her pain, and smites the young girl. When Castiel realizes what he and Dean are dealing with, he tells Dean that the Riet Zien method of smiting is "so quick and so total that it rendered death virtually painless."

9.09 Holy Terror

As prospective vessels for Bartholomew followers gather at a campfire, and prepare for their angelic possession. Followers of Malachi proceed to launch a sneak attack, killing the angels present while smiting the intended vessels before they could be possessed.

11.09 O Brother Where Art Thou?

When the angels decide to take the fight to Amara. The Head Angel is able to locate Amara, and with two others by his side, he demands that Amara surrender to the judgement of Heaven, telling her if she resists each and every angel in the skies will smite her, in a single unified blow. Amara in turn kills the three angels one by one, and when the skies began to crack with thunder and lighting and clouds begin darken to swirl, Amara gives one last look of concern to Dean before she sends him away and takes the angel smiting head on with her arms wide open as a blaze of holy light envelops her and the ground explodes.

11.22 We Happy Few

While discussing how to defeat Amara with God and Lucifer, Dean remembers that the angels mass-smiting actually hurt Amara. As a result, Lucifer and Castiel recruit the angels to perform another mass-smiting to help defeat her. After five witches hit Amara with a magical attack, Heaven sends down another mass-smiting which Amara once again takes without resistance. Though not having an effect on her to the same degree as the first time, Amara is weakened by the blast, allowing a mass demon attack and a strike by Lucifer with his spear to defeat her.