You become a fighting machine—stronger, tougher, faster, and more skilled in combat. Your mind-set changes so that you relish combat and you can't manifest powers, even from psionic items (and you cannot cast spells, even from magic items).
You gain a +4 enhancement bonus to Strength, Dexterity, and Constitution, a +4 natural armor bonus to AC, a +5 competence bonus on Fortitude saves, and proficiency with all simple and martial weapons. Your base attack bonus equals your character level (which may give you multiple attacks).
You lose any ability to manifest powers, including your ability to use command thought, use-activated, or power trigger psionic items, just as if the powers were not on your class list. You likewise lose the ability to use spell trigger or spell completion magic items.
If you spend 4 additional power points, the natural armor bonus increases by +1 and the competence bonus on Fortitude saves increases by +2.