Avengers: Age of Ultron just grew by one, with another villain joining the fray. According to THR's Borys Kit, Thomas Kretschmann (Dracula) has joined the cast of the Avengers sequel as Baron Wolfgang von Strucker, the longtime Captain America villain. Variety later corroborated the news.
von Strucker has great ties to the Marvel Cinematic Universe already, having, in the comics, been a villain for both Cap and directly for Nick Fury. He also has led Hydra, been a Nazi officer, and has fought with everyone from the Avengers to the X-Men to Spider-Man in the comics (though the latter two obviously can't come into play here). He also has ties to the Thunderbolts, opening up another venue for expansion in the MCU.
Kretschmann joins James Spader as the villains for the film (so far), with Spader playing the titular Ultron, a robot created for the betterment of mankind who gains full sentience, goes rogue, and instead decides to exterminate organic life. The main cast of Avengers is returning, and being joined by Aaron Taylor-Johnson and Elizabeth Olsen as the brother-sister duo of Quicksilver and Scarlet Witch.
Avengers: Age of Ultron is due in theaters May 1, 2015.