Paragon

Other Fighters spend their time learning complex techniques or elegant maneuvers. You however dedicated your time to training your body. This dedication has allowed you to surpass the widely accepted peak of physical capability. 

Self Improvement

Beginning at third level when you choose this martial archetype, choose either Strength, Dexterity, or Constitution. The chosen stat is increased by 2 as well as having its maximum score increased by 2. Alternatively with the DM's permission, you may take a feat. You get this feature again at levels 10 and 18. On either subsequent repeat of self-improvement, you may pick a stat other than the one already picked, or you may pick the same one.

Uncanny Talent

Beginning at 7th level, you may choose to reroll one skill check the adds your Strength, Dexterity, or Constitution modifier. You may choose to do this after you see the dice roll but before you know the results. Once you use this class feature you may not do so again until you have finished a long rest.

Compensation

Starting at 10th level, whenever you use your indomitable feature, you may replace the stat modifier used with your Strengths, Dexterity, or Constitution modifier. Note that using this feature does not grant you Proficiency in the saving throw unless you already had it.

Empowered critical

Starting at 15th level, your natural abilities shine through on your most powerful attacks. Whenever you roll a 20 on an attack roll, you gain an additional bonus to damage rolls against the target for that attack. The bonus is equal to either your strength or dexterity modifier. 

Peak Form

Once per short rest, after missing a creature with an attack roll, you may choose to add a bonus to the roll equal to either your strength or dexterity modifier.