Multifaceted Combatant

Most only have one path of attack and damage.  Even those who know more then one keep them separate.  You, on the other hand, have learned to use more than just a single ability in your martial combat.

Choose one from Strength or Dexterity.  Then choose one other core ability, this can also be Strength or Dexterity, whichever one you didn't pick.  Add both ability modifiers to your melee Atk/Dmg rolls.