Check out this interesting interview with Tom, posted by Collider, discussing coming back to the Marvel universe as Loki after a hiatus, and the evolution of the character.

At the end of Thor: The Dark World, Loki’s got everything he ever wanted.  How has it gone for him since?

You’ll have to wait and see. That question is answered in this film, so I’m loath to tell you because I think it’s surprising and fun.  But yeah, you’re right.  He finished Thor: The Dark World on the throne and it’s taken awhile for anyone to catch on…

Has Loki changed at all?

Yes, but that’s in his nature. He’s a mercurial spirit, and the minute you try to define him, he changes shape. Events in Ragnarok do try and inspire him to change forever… The Goddess of Death shows up, and the stakes are high for everybody, so Loki, perhaps more than ever, is challenged to define himself in the face of that threat.

Read more of the story at Collider’s website.