Changes

* [[Telekinesis|Telekinetic]]<ref name="four09" /><ref name="four15" />* Can [[Possession|possess]] humans.<ref name="four09" /><ref name="four15" />* Has high resistance to [[Ruby's knife]].<ref name="four09" /><ref name="four16" />

* Unaffected by the smiting powers of [[angel]]s, though their [[grace]] can destroy his current [[meatsuit]].<ref name="four10" />* Can overpower [[angels]],<ref name="four10" /> though he does not possess the power to kill themand they can overpower him if he is sufficiently distracted.<ref name="four16" /><ref name="four15" />

* Is vulnerable to [[devil's trap]]s.<ref name="four16" />* Can be hurt by ingestion of [[holy water]] and [[salt]].<ref name="four16" />* Can be killed by [[Sam]]'s powers if Sam has recently consumed by Nathan[[demon blood]].<ref name="four16" />

Alastair leaves [[Hell]] and [[Possession|possesses]] a pediatrician to capture and interrogate [[Anna]]. He follows [[Sam]] and [[Dean]] from Anna's house to the church Anna is hiding at. [[Ruby]] tries to get Sam, Dean, and Anna to leave as quickly as possible to avoid Alastair, but realizes that it is too late when signs of his approach break out, including a statue of the virgin Mary weeping blood. Although she convinces Sam to [[exorcise ]] Alastair with his powers, they have little effect on Alastair, who uses [[telekinesis]] to fling Sam down the staircase before attacking and overpowering beating Dean. He taunts Dean about their "closeness" in Hell, prompting Dean to finally recognize Alastair, even in his [[meatsuit]]. Sam returns to stab Alastair with [[Ruby's knife]], but much to the Winchesters' horror, the [[demon]] does not die. As Alastair pulls the knife out, Sam and Dean flee from him by jumping out the church window and he allows them to escape so that he can use them to lead him to Anna again.

Alastair is described by [[Ruby]] tells [[Sam]] that Alastair as a master torturer who is "practically the Grand Inquisitor" in [[Hell]] and that , whom she is more scared of him than even the [[angels]]. She suggests that After her suggestion to abandon [[Anna]] and run from Alastair gets rejected, she tries to get [[Sam ]] to resume drinking her [[Demon blood|blood]] so that he can successfully [[exorcise ]] Alastair, but . Sam refusesthis as well. Later on, Alastair reappears when Ruby fulfills leaves to fulfill her part in Sam's plan by , burning her [[hex bag]] and letting Alastair find herat a [[crossroads]]. Alastair derides her , a fellow [[demon]], for protecting Anna, an [[angel]], when she is a [[demon]], and rejects her offer to trade him Anna for the safety of herself, Sam, and [[Dean]], instead capturing . He just insults her again before having his minions capture her and he begins torturing her with [[Ruby's knife|her own knife]] to force simply make her to tell him where Anna is. While torturing her, Alastair reveals that he actually vastly prefers Hell to Earth (which he loathes), having only left it because he must deal with "this nasty angel business." Eventually, Ruby leads agrees to lead him and his minions to Anna; - she is unwilling to simply tell him what he wants to know because she knows that he would just kill her afterwards. Alastair and his minions accompany her and find that [[Castiel]] and [[Uriel]] are also at the site and are , about to execute Anna. Dismissing Contrary to the terror other [[demons]] showed of angels, Alastair dismisses Castiel's warnings that they will be killed if they do not leave, the [[demon]]s and even trades insults with Uriel before leading his forces to fight the angels to and stop them from killing Annaso that he may capture and torture her. Although Alastair's his minions are quickly killed by Uriel, Alastair proves too powerful for Castiel to smite and overpowers the angel, which shocks the latter. When Dean hits him over the head with a crowbar, Alastair shifts his attentions to him and Sam and launches a [[Telekinesis|telekinetic]] attack on their hearts while chastising Dean about his lost "potential." He tries to intervene when he sees Anna regain her [[grace]], only to get vaporized instead, leaving behind only Ruby's knife. Later, Dean tearfully reveals to Sam that after every day of torture in Hell, Alastair would offer to stop if Dean agreed to torture other souls; although . Although Dean held out for the first thirty years (three months on Earth), he eventually gave in because he couldn't take it anymore and spent the last ten years of his time there (one month on Earth) torturing other souls under Alastair's instruction.[[File:Alistair with Death's weapon.Jpg|350px|thumb|left|Alastair in his new [[meatsuit]], preparing to break one of [[the 66 Seals]].]]

Now Alastair is once again made to leave [[Hell]] and assist in a new the [[meatsuitApocalypse]] (, much to his previous one having been destroyed by dissatisfaction. Now in a new [[Annameatsuit]]), Alastair he is attempting to break one of [[the 66 Seals]] by killing two [[reaper]]s under a solstice moon. He confronts [[Dean]] and [[Sam]] in a cemetery, revealing that he had survived his encounter with [[Anna]], though the pediatrician he had been [[possessing]] did not, and gloating that the latter's wife is still looking for her husband and unaware he is dead. Trying again to kill them, Alastair telekinetically throws Dean into a gravestone and injures Deanhim, but finds that Sam is resistant now immune to his powers and fights back, revealing that he survived his last encounter with Anna. He flees when Sam tries to [[exorcise]] him with his powers , and later returns in yet another meatsuit. When the boys become non-corporealto better find the demons holding the reapers hostage, and therefore they track Alastair down at a funeral home warded in [[Enochian]] against [[angels]]. As they have made themselves subject to [[ghost]]ly weaknessesin their spiritual state, they track Alastair down at a funeral home and he traps them with an [[iron ]] chainand toys with them by shooting them with [[salt]] as he sends a minion to kill their unconscious bodies. He kills While their ally [[Pamela Barnes]] is able to hold off Alastair's servant for a time and thwart this aspect of Alastair's plan, she is fatally wounded by Alastair's servant in the process and later dies. Meanwhile, Alastair begins breaking the seal and succeeds in killing one [[reaper]] with [[Death's scythe]], but though the boys rescue help [[Tessa]], preventing escape and ultimately save the seal from being brokenbefore fleeing. Later Alastair later tracks Dean down alone as Sam is fighting off Alastair's minion in attempt to save Pamela. As he confronts begins closing in on Dean, Alastair vanishes again as he is captured by [[Castiel]].

Alastair is captured has held captive by [[Castiel]] and [[Uriel]] and imprisoned in a [[devil's trap]]since the previous episode, but he refuses to tell them anything about the slain [[angel]]s. [[Dean]] is recruited as an interrogator because he was formerly Alastair's student during his time in [[Hell]]. After extensive Amused by the idea, Alastair taunts him over the course of the torture session, though he concedes that reality is "too concrete" compared to Hell for Dean to adequately torturehim. Dean instead tortures Alastair with [[holy water]] injected into his veins, [[salt]] poured down his mouth, and mutilation from [[Ruby's knife]], as he admits to an unnerved Alastair he'd dreamed of doing in Hell. Instead of giving Dean the information he asks for regarding the angel murders, Alastair breaks free Uriel having sabotaged messes with Dean by claiming that he tortured Dean's father [[John]] in Hell and even made him the same offer he'd made Dean, but that unlike his son, John was a "hero" who steadfastly refused and ultimately escaped after 100 years (one year on Earth) of Alastair's torture. Alastair gloats that when Dean accepted the offer and began torturing souls, he broke the first of [[the 66 Seals]] and enabled [[demons]] to begin breaking the rest of them. Having kept an eye on the devil's trap to prevent his role he's caught in the angelic deaths being compromised - later revealedto be Uriel's doing, to let Alastair kill Dean and escape to make the angels keep thinking the demons are responsible for the angel murders when it is really Uriel himself - Alastair escapes when a devastated Dean turns his back, then begins savagely beating Dean again. He almost kills is about to finish Deanoff and send him back to Hell, telling him he has a lot to learn, but is stopped when he becomes distracted by Castiel, who intervening. Castiel throws [[Ruby's knife]] and embeds it in Alastair's chest. , but Alastair simply pulls the knife out and fights Castiel. He manages to trap him against a pillar, again overpowers Castiel and admits that while he is unable to kill the [[angel]]as he admits he wishes he could, he will reveals that he can send him back to [[Heaven]]. Alastair begins to chantan angel [[exorcism]], but he is stopped by [[Sam]], who has become strong enough through his consumption of [[Ruby]]'s [[demon blood]] to overpower even him with ease. Agonized by Sam forces 's psychic torture, Alastair finally reveals that he knows none of the demons, including himself and [[Lilith]], are responsible for the angel deaths. Knowing that Sam can psychically [[exorcise]] demons, he challenges Sam to exorcise him back to Hell, where he wants to talkbe, then kills but is shocked when Sam instead uses his enhanced power to kill him via his abilities.

Alastair's death is brought up by [[Dean]] , who reveals that [[Castiel]] has told him about [[Sam]] torturing using his powers to torture and killing kill Alastair with ease. Dean thinks that this Sam being able to do so is one of the signs another sign that Sam he is going dark-side.

Alastair is again mentioned by [[Dean]] points out , who is in disbelief that [[Sam]]'s powers used to be were strong enough to kill Alastair but are now not even strong enough to kill a low-level [[demon]]. The reason, unknown to Dean at the time, is that Sam has not recently fed on [[demon blood]] due to a prolonged absence from [[Ruby]].

While undergoing forced withdrawal from [[demon blood]], [[Sam]] has several hallucinations, the first of which is Alastair inexplicably returningin his last meatsuit. Finding Sam hallucinates that he is strapped down and tortured by locked in [[Bobby's Panic Room]] alone with him, Alastair tortures him with a knife, but eventually . Eventually Alastair disappears and Sam realizes that he is had hallucinatingboth Alastair and the torture.

Alastair is the only [[demon]] explicitly mentioned by [[Ruby]] reveals when she is explaining that not even Alastair none of the others besides herself and [[Lilith]] had known that she was working of her undercover mission for [[Lucifer]] and [[Lilith]].

To prove that she is capable of making [[Crowley]] give into her demands, [[Meg]] reveals that she had apprenticed under Alastair in [[Hell]] like [[Dean]] had, and Dean grudgingly concedes that this means she can make Crowley do whatever she wants. Meg doesn't reveal when she undertook this apprenticeship, but it must have been before Alastair's capture in [[4.15 Death Takes a Holiday]], as he was killed in [[4.16 On the Head of a Pin|the following episode]]. She is known to have been in Hell in the time between her [[exorcism]] in [[1.22 Devil's Trap]] and her return for revenge against the Winchesters in [[2.14 Born Under a Bad Sign]]; if his words in [[4.16 On the Head of a Pin]] were true, he would have also been working on torturing and trying to tempt [[John]]'s [[soul]] at the time. Alternately, Alastair may have taught her previously in Hell at some point [[pre-series]].

Alastair is mentioned by [[Crowley]] mentions Alastair when listing off those who underestimated the threat the Winchesters pose and paid the price for it, along with [[Lucifer]], [[Michael]], [[Lilith]], and [[Azazel]].