The Master is somewhat a pushover. He doesn't deal too much damage, as long as you are wearing the Power Armor and as long as he doesn't hit you with a critical attack. If he does, most certainly you will lose (when he hit me with a critical, it damaged around 190). But what is the real and constant problem is his guards, that keep respawning, even more when they are armed with Plasmas Rifles or Power Fists, since they deal moderated damage even against Power Armors. Note that you don't need to face the last boss, as there is at least 2 other ways to "defeat him", without engaging him in combat, and clear the game, as long as you have the skills and items needed.
seeGAMEPLAY