Realignment

Due to either meeting a skilled wizard, Blacksmith, battle experience  or what what reason you choose. You are now able to choose any ability score to calculate your armor class. So instead of calculating it as 11 + your Dexterity modifier (add proficiency bonus if proficient with light armor) you could substitute a new Ability score in its place. Example 11 + your Constitution modifier (add proficiency bonus if proficient with light armor). This would be true for all 3 armor modes.

Benefits: +2 to chosen ability 

                 New Armor class