No being has ever been introduced on Supernatural for them to be good guys, as every one of them ends up as antagonists at some point. The ones who are the most striking example are the angels, who were established as generally being villains under the guise of Heaven’s protectors.
This makes them worse than demons in some ways since the latter beings are at least open in their antagonism. During their time on the show, the angels have been seen committing terrible acts and being largely apathetic towards them. Here are the worst things they’ve done, either individually or as a unit.
Sending Dean To An Apocalyptic Future
When Dean became disillusioned with the apocalypse scenario and lost faith in his relationship with Sam after the latter brought Lucifer back, he was apprehended by Zachariah and sent five years in the future. Here, Dean found out that Lucifer had taken over Sam and was successful in bringing the apocalypse about, even killing future Dean.
However, the angels’ motive hadn’t been to make Dean reconcile with Sam; rather, they had every intention to leave Dean locked forever in a loop to the future if he didn’t do what they wanted. Dean might have been stuck in endless apocalyptic scenarios had Castiel not rescued him.
Controlling Castiel's Mind
Castiel’s return from Purgatory didn’t go as great as he planned, as his mind was taken over by the intelligence agent Naomi. Since she wanted him to spy on the Winchesters, Naomi had a backdoor in Castiel’s head at all times.
When she came upon the conclusion that Dean was a liability, Naomi ordered Castiel to kill him, with Sam to follow after that. This was especially vicious of her since she knew the Winchesters were the only ones Castiel loved, yet she not only mind-controlled him with orders to kill, she even had Castiel beat Dean to a pulp simply because she enjoyed it.
Turning Against Their Own Kind
It’s become countless by now the number of times the angels have stabbed their own kind in the back, what with the many civil wars in Heaven that also spill out on Earth. Castiel himself was guilty here too, as he proceeded to slaughter thousands of angels in the Season 7 premiere.
We saw the first instance of an angel turning evil on their siblings in Uriel when he began killing his kind covertly after becoming disillusioned with Heaven and turned toward Lucifer’s side. This has become a habitual thing with other angels, as we’ve seen more than dozens of occasions where they've been happy to use the angel blades.
Complete Mass Killings On Heaven's Orders
When the demon Samhain was about to rise from Hell after centuries, Sam and Dean were informed that it was one of the 66 seals of Lucifer’s cage. In order to avoid that seal from breaking, the angels also revealed their plans to destroy the town they were in.
Naturally, this horrified the brothers as there were thousands of innocent people there who would lose their lives without any effort put by the angels to prevent Samhain’s rise. Even Castiel, who had some doubts, was initially willing to flatten the town if it meant the goal was achieved. The crazy thing is that the angels confessed that this was far from the first time they had finished off a town.
Metatron Causing All Angels To Fall
Sure, Metatron was to blame for what happened to angels in the finale of Season 8, but he was also justified in some way. His reasoning to cause every angel to lose a significant amount of their powers and fall to Earth was because the angels had earlier did him wrong.
Since Metatron had been God’s scribe, he had been blamed when Chuck left Heaven without warning. For casting him out of his home and wrongly convicting him, Metatron responded through his revenge, which claimed the lives of seemingly hundreds of angels.
Trick Humans Into Becoming Their Vessels
While it might sound as if angels are better than demons since they ask for their vessels’ consent before possessing them, it’s not really as innocent of a process as that. This was first shown when Castiel took possession of Jimmy, who later itted he had been falsely led to believe he would be fighting for a good purpose.
Castiel can be justified as he himself was led astray; however, we’ve seen more sinister intentions from angels, such as when Bartholomew and his crew made fanatics believe they were completing god’s will, only for the same vessels to later die and their deaths to not mean anything.
Destroy The Apocalypse World
If you want to know the worst the angels are capable of, then the best example would be the alternate world shown in Season 13, which was dubbed the Apocalypse World. This place showed the effects of a takeover by Michael, resulting in complete chaos.
Even the skies seemed to be scorched here, as Michael and his followers abandoned all order and proceeded to slaughter seemingly for sport. This world was so far gone that, following the exodus of a few survivors, it was left completely abandoned.
Manipulate A Soulless Jack
When left to their own devices, the angels have always been shown to be a violent bunch devoid of any sense of empathy. In Season 14, with very few angels now left, Duma seized control of Heaven and brought about a bloody rule.
Moreover, she manipulated Jack’s soulless condition by making him kill off people who weren’t following Duma’s rule. She also established a reign of terror by using fear as a bargaining tool, threatening to destroy John and Mary’s Heaven as an act of aggression.
Plot To Bring Lucifer Back
The cluelessness the angels have over human emotions has been a source of humor on the show, but this has also been used as a way to make people underestimate the angels so that they can carry out their secret plans.
One of these involved the plan of bringing Lucifer back, where Archangel Michael worked with the demon Lilith to have Sam open the cage. They knew this would’ve resulted in half of the planet being scorched if the fight between Michael and Lucifer took place, but this was only shrugged off by the angels as necessary collateral damage.
Attempt To Coerce Dean Into Saying "Yes" To Michael
Giving consent to being possessed isn’t exactly an advantage for a potential vessel, not when they can be strong-armed into providing their consent. The worst occasion this was employed was when Zachariah took extreme measures to make Dean say “yes” to Michael.
Here, he shed away all of his fake friendliness by torturing Sam and Adam in front of Dean, with stuff like breaking their bones and taking away Sam’s lungs. Zachariah also beat up Dean himself, seeing as he just wanted the meat suit and not the person, calling Dean a “maggot” who ultimately meant nothing.