Marvel Entertainment premieres its third motion comic “”Iron Man: Extremis”” today as part of its Marvel Knights Animation lineup.

Terrorists steal and inject themselves with a bioengineered serum called Extremis. One of them transforms into a human-machine hybrid strong enough to challenge Tony Stark and his Iron Man armor. Stark must not only confront this new threat but also his seeming failure to improve the world with research funded by his company.

“”Tony constantly questions himself (about) what his role is as Iron Man or as CEO of Stark Industries, or just his general role as a human being in the world and what he should be doing in his life,”” said Ruwan Jayatilleke, senior vice president for development & planning, print, animation and digital media at Marvel Entertainment.

The original comic book by writer Warren Ellis and artist Adi Granov recasts Tony Stark’s origin story for the 21st century and was used in the first “”Iron Man”” movie. As lead producer for “”Iron Man: Extremis,”” Jayatilleke was aware of the strong impression the movie had on its audiences.

“”Robert Downey Jr. owns the voice, look … and basically lives and breathes Tony Stark/Iron Man. Being able to cast an actor who can evoke those sorts of feelings but still make this project very distinct and unique from the ‘Iron Man,’ ‘Iron Man 2′ movie experiences is a challenge all in itself,”” he said. “”But I think the actor DJ Tanner did a really good job of getting that breadth and width of the character and also making sure he added his own … personality to the Tony Stark character.””

Similar to its first two motion comic projects, Brian Michael Bendis and Alex Maleev’s “”Spider-Woman”” and Joss Whedon and John Cassaday’s “”Astonishing X-Men,”” Marvel uses animation, special effects, sound, music and voice acting to recreate the original comic book and attract a mobile video audience.

“”It is a challenge making sure that this project not only honors the work that (Ellis and Granov) did but enhances it as well and gives a different entertainment experience. … We’ve been really lucky in having great source material,”” Jayatilleke said.

“”We definitely could have gone with a less full, less robust approach to it and phoned it in,”” he added. “”But I think part of creating this motion comic is to make sure that (each part) of the project was as full and rich as any other aspect of the motion comic.””

In addition to releasing motion comics through iTunes and Xbox Live for the first time, Marvel Entertainment plans to reprint — later this year — hardcover editions of “”Astonishing X-Men”” and “”Spider-Woman”” with DVDs of their respective motion comic, Jayatilleke said. The company also plans to expand its efforts in the relatively new field of motion comics.

“”If we’re going to go into (making motion comics), we want to have a definitive role in defining it. We definitely didn’t want to wait on the sidelines for a few years and see how it played out — and then come in and play by someone else’s rules,”” Jayatilleke said.

Like other media companies, Marvel Entertainment has to compete for the eyes and ears of an audience accustomed to multimedia content, whether it’s a TV episode on Hulu.com or a podcast through iTunes. So why would anyone consider watching “”Iron Man: Extremis”” rather than just reading the comic books or waiting for “”Iron Man 2″” movie?

“”If someone sits there and really watches the first episode, they’ll definitely get an immersive experience in who Tony Stark is and the challenges of being Iron Man in this … society that is overly reliant on technology,”” Jayatilleke said.

The first episode of “”Iron Man: Extremis”” is available today for download through iTunes, Xbox Live and Zune. It is intended for mature audiences. Visit http://marvel.com/extremis/ to watch each episode and to see a complete release schedule.