Boon of the Impertinent Scholar

Viewing yourself as superior, your scholarly presence accommodates your rising power. Looking down at those beneath your level of intellect, their feeble minds fail to find any gap within your stance.

 
Upon starting your Bladesong, you enter an Impertinent Stance that lasts until your Bladesong ends.
While you are in this stance, each time you attack, are attacked or subjected to a saving throw by a hostile creature, you gain an amount of charges equal to the difference between your and their intelligence score, potentially even leading you to lose charges.
The maximum amount of charges you can gain from one instance is equal to half your Intelligence Modifier rounded down.
You have 0 charges each time you enter your bladesong, and return to 0 charges when it ends.
You can hold a maximum amount of charges equal to your Intelligence Modifer + Proficiency Bonus.

You gain the following effects based on how many charges you currently hold.

4 Charges: At the start of your turn, you may expend any number charges as a free action in order to grant yourself THP equal to the amount of charges expended times your Intelligence Modifier. If damage would exceed these temporary hit points, it does not roll over to your hit points as normal, as your stance grants you improved resilience.

8 Charges: In order for your spells to be counterspelled or dispelled, creatures must pass an Intelligence Saving throw against your Spell Save DC first, as your magic has been interwoven with your dance and warded.

12 Charges: You have a bonus to your Attack Rolls, Saving Throws and Armor Class equal to half your Intelligence Modifier rounded down.