When Joss Whedon announced he was adding two new characters to 'Avengers 2' in the brother/sister team of Quicksilver and Scarlet Witch, fans couldn't help but immediately start speculating who would be cast as the new additions to the team. Previously, we reported that Irish actress Saoirse Ronan was the top choice for Scarlet Witch and now we know who Whedon and Marvel have their eye on to play Quicksilver. And it's a name superhero movie fans will definitely be familiar with.

According to The Wrap, Aaron Johnson, known to many as the title character in 'Kick-Ass,' is the frontrunner to star in 'Avengers 2' as Quicksilver, though no final decisions have been made and contract talks haven't yet begun.

Quicksilver is the lightning-fast Pietro Maximoff, brother of Wanda, also known as the Scarlet Witch. But, because director Bryan Singer recently added his own Quicksilver in 'X-Men: Days of Future Past' (played by 'American Horror Story' actor Evan Peters), it's unclear whether 'Avengers 2' will actually be able to refer to him as Quicksilver in the film (both Marvel and Fox have the rights to use the character, though Marvel cannot refer to him as being a mutant).

In another interesting 'X-Men' / 'Avengers 2' twist, Fox originally wanted Johnson to star in 'X-Men: First Class' as Cyclops but that never materialized and now Marvel has swooped in to snatch him up for their superhero franchise. What this means to his future in the 'Kick-Ass' films remains to be seen.

Whedon has previously said that he hopes to begin filming on 'Avengers 2' in January of 2014 for a May 3, 2015 release date.

Johnson can be seen this summer in 'Kick Ass 2: Balls to the Wall.'

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