Is there an idiom that allows you to express this idea? I am either trying to find an idiom, or a word, or an adjective that I can use in a phrase during a casual conversation. As long as you manage to convey the idea in a good-sounding way, I would be okay with anything.
The only way I could express this is the following way:
This guy would not give any inch, and is ready to die for it.
The above doesn't sound too idiomatic and the "it" may be a bit ambiguous.