Look, it's the new recruits of Earth's Mightiest Heroes!

Yes, we are pumped for the return of the superhero ensemble in "Avengers: Age of Ultron," but it's the addition of the brother-sister duo, Scarlet Witch (above) and Quicksilver (below), that's inspiring even more geek-outs.

Sibling rivalry — and sibling bickering — is right up writer-director Joss Whedon's alley, and all the better that it will be embodied by such fan-approved thespians as Elizabeth Olsen and Aaron Taylor-Johnson.

View photos Elizabeth Olsen as Scarlet Witch More

The two young stars, who will also be appearing together in this summer's "Godzilla," were spotted in costume and in action on the Aosta, Italy, set of the highly anticipated sequel.

View photos Aaron Taylor-Johnson as Quicksilver More

Taylor-Johnson as Pietro Maximoff/Quicksilver looks especially, well, "Kick-Ass" as the super-speedy superhero, sporting athletic gear recalling the color scheme of the more stylized outfit worn by his comic book counterpart. (But we're not quite sold on that wig...)

Elizabeth Olsen is dressed decidedly more conservatively than her four-color alter ego, Wanda Maximoff/Scarlet Witch. In these new images her pose is ripped straight from the comics, down on one knee and working one of the Witch's many hexes with her hands — probably right in a bad guy's face.

View photos Elizabeth Olsen and Jeremy Renner More

Plus that's Jeremy Renner's Hawkeye next to Scarlet Witch as they do battle with the forces of the villainous sentient robot Ultron (James Spader). As you can see, Ultron's nefarious plans include leaving a perfectly good television set on the ground and spreading newspaper pages and other debris all to and fro.

And speaking of Ultron, some set pics provide what may be some early looks at the title villain... or at least the stunt/motion-capture guy who is standing in for the super-powerful robot (we doubt that's James Spader in that outfit, if that is indeed Ultron). We're assuming that the final version of Ultron is going to be a lot more impressive (and a lot bigger), but these pics may reveal an idea of what to expect when it comes to the main source of "Avengers" antagonism.

View photos