I don’t see a problem with justifying your actions as revenge or justice.
Discussion
Laws don't cover everything. Sometimes it is ok to not follow a law. Often acting from justice/revenge comes over as weakness to me. Depends on the context though.
Can you give me an example of how seeking is a weakness?
I don't feel like going to deep into this topic right now. It depends on from what mindset it came.
Often dialectics can be used to be proven correct, but there are different perspectives. Truth can always be disproven. Absolute truth does not exist, see "The Münchhausen trilemma". Even math is just based on assumptions.
I can give you this video if you are interested. A summary of "The Genealogy of Morals". But such ideas are not that easy to explain through one post. The Nietzsche Podcast is a pretty good source. Most YouTube videos are not.