Fighter's High

As a Barbarian, Fighter, or Paladin, you have grown to crave and love combat. Through these experiences, you slowly start to enter a special "zone" of sorts that over time increase your combat abilities.
Every time you kill an enemy, rather land the final blow, you gain +1 score bonuses to add to your roll for any Strength or Dexterity based ability checks in an encounter. The more enemies you kill in an encounter, the greater the bonus you receive. These bonuses disappear once the encounter is over. 
You also gain +1 to both Strength and Dexterity ability checks simply by applying this feat.