The power levels usually only run from 6,000 to 12,000. None of the Nagadarr are as powerful as you suggested. Their armor and weapons give them an added advantage, but one that can be circumvented.
If you are basing it on Meagan's fight, don't. She isn't fully aware of her own power and she panicked. Grin was about 9,000 and Meagan was about 7,500. A Basic Kaio-ken would have more then handled him, but she went overboard and used x1.5, level 2 Kaio-ken.