take no prisoners
to be very determined and not care about other people's feelings when trying to achieve something
Quel serait un équivalent français de cette locution ? « ne faire aucune concession » par exemple ?
Some phrases for context:
It was just an absolutely take-no-prisoners approach.
(In Rock's) Side two opened with the searing power chords of "Flight of the Rat"; another example of the band's new take-no-prisoners hard rock stance, though at nearly eight minutes, it too found room for some extended soloing from Blackmore and Lord.