Alastor is a member of JADOW, the organization which all bosses in the game are part of, but doesn't care about their ideals. He merely wants the ultimate battle. He faces Joe twice, first disguised as him as the fourth level boss, ("Another Joe," an imposter Joe,) and again as himself at the end of the next level. He comments that Joe's attacks are "viewtiful" which inspires Joe to call himself Viewtiful Joe.
Alastor returns in Viewtiful Joe 2, after dispatching the Tyrannosaurus rex samurai Big Lee, (who claims he isn't the other T-rex, Big John,) so that he can fight Joe instead. Unlike the other bosses in VJ2, Alastor is not part of GEDOW. After a quick defeat, Alastor is transformed into Underworld Emperor Alastor due to the power of the Black Film. In this form, his voice is much deeper and he shares several physical traits with Dante's Alastor Devil Trigger. Alastor repeats the sword's lines from the original Devil May Cry and transforms into an Alastor sword. After unsuccessfully trying to impale Joe the same way he did to Dante, Alastor does battle with Joe and Silvia, but is once again defeated.
In the third game, Double Trouble, Alastor appears once more to challenge Joe and even uses a mecha similar to Joe's Six Majin called Rex Majin. In the end, Alastor is defeated but takes a blow from Queen Heinderella to allow Joe to escape. As he disappears, Alastor says that Joe can only allow himself to be defeated by him. As in VJ2, Alastor is not affiliated with the main villains, MADOW.
In the series, there seems to be a running gag where Alastor "dies" honorably, only to reappear and lament about his lack of screen time. In VJ, he does this to the players directly; in VJ2, he instead falls out of the movie screen and talks to Joe's father, Jet Black.
Alastor uses a number of Alastor the Thunder Devil's attacks.
- Air Raid - The basic lightning attack from the DT form.
- Stinger - Charging attack, also from the DT form.
- Round Trip - The swords appear as Alastor.
- Vortex - A full-body spinning attack usually used twice in succession.
- Ultra Violet Kick - The same as Joe's Red Hot Kick, only clad in Alastor's signature purple lightning.
References to Devil May CryEdit
- All of Alastor's attacks.
- The poster for the Alastor chapter is a parody of the Devil May Cry cover with Alastor in place of Dante.
- Alastor's human form has him wearing a purple suit that mirrors Legendary Dark Knight Dante's outfit. This outfit is also available in Viewtiful Joe: Red Hot Rumble and was shown in the second season of the anime.
- When playing as Alastor in Viewtiful Joe, the player must "Devil Trigger" to transform into henshin form. In his story, where he replaces Joe, he must rescue Goldie, the twin sister of Joe's girlfriend, Silvia. In gameplay, he shouts "Air Hike!" while double jumping.
- Dialogue with Dante in the PS2 version implies that Alastor is the spirit in the sword, and further dialogue in Red Hot Rumble clarifies this as true. Alastor bears a grudge against Dante for forcefully throwing him into a Marionette without apologizing and for not taking him to "Somewhere Island," a reference to the second game.
- In Red Hot Rumble, he has a form called, Stylish Alastor, which has two costumes with white hair; one wears red and the other wears blue, in reference to Dante and Vergil.
- The lightning used for Alastor's attacks is the same as that in Devil May Cry.
- In Okami, another game directed by Hideki Kamiya, a fireworks expert calls one of his masterpieces "The Midnight Thunderboy," which is Alastor's nickname and the title of the chapter in which you face him.