He is 'seeking revenge for' his father's murder. [=he wants to harm the person who killed his father]
He swore to 'take (his) revenge on' his enemies. [=to harm his enemies]
The bombing was 'in revenge for' the assassination of their leader.
(..) rich beyond belief. And that wasn't even the best part. Oh well, C'est la vie. Enjoy your crown. What's the best part? It comes with revenge on Flynn Ryder. So you're being strangely cryptic as you wrap your magic hair around my injured hand. Sorry. Just don't, don't freak out. (..)2010 Tangled