Theo's evil plans on Teen Wolf just keep getting more and more mysterious. One minute, he's desperate to steal Scott's pack, the next minute he has his own pack of Dread Doctor-made Chimeras. In "Codominance," a new part of Theo's master plan was revealed: he's looking for a blind alpha. That's right, Theo is looking for Deucalion, our old friend from Season 3. As to why Theo is looking for Deucalion on Teen Wolf , we can only guess, but I'm pretty sure it's not good.
For those who might have forgotten about Deucalion, he's the blind alpha who led a pack of alphas in Season 3. Deucalion and his super scary Alpha Pack — who gained acceptance into the pack only after killing one of their own Betas — went up against Scott and Derek, propelling Scott to become a True Alpha. During his time in Beacon Hills, it was revealed that Deucalion had known Talia Hale, Derek's mother, and that he had a big feud with Gerard and the Argents. Gerard was actually the man who blinded him — ouch! Scott and Derek let him go in the end, threatening to track him down and kill him if he ever went over to the dark side again, and Deucalion left Beacon Hills in peace. If you still don't remember, see below (he's the one crushing the other guy's skull).
So, all this history tells us who Deucalion is, but it still doesn't explain what Theo wants with him. Before Theo's master plan of searching for Deucalion was revealed (Mason's new Chimera boyfriend FTW), Theo was complaining to the Dread Doctors about his new pack. Theo assumed that having a pack of Chimeras would automatically make him an alpha, like Scott, but he was wrong. His eyes still glow yellow, and, as he so brilliantly pointed out, he's not even a real werewolf. This suggests that he wants Deucalion to show him how to become an alpha. After all, Deucalion became a strong and powerful alpha by killing his own beta, so he knows a thing or two about how the alpha line works.
Looking at the trailer for Season 5B, however, it seems like Theo's plans for Deucalion might be even bigger. When Theo was talking to the Dread Doctors, he hinted that he wanted them to give him La Bête, to let it become part of his pack. And, in the 5B trailer, Deucalion is heard talking about La Bête and telling Theo, "You think that I'm going to show you how to steal its power."
Theo doesn't just want to control La Bête (aka The Beast), he wants to become it.
Images: MTV; teenwolf/tumblr