Starscourged Might

Amidst the endless cosmos, there are those capable of shaping the stars themselves. Influencing the night sky itself, their work affecting all of those that look up at it, these forces take on the shapes of various different phenomena to observe. Black holes, nebulae, supernovae, the power they harbor immense; and now a strength that you can begin to generate and harness yourself. 
What you are to make of it, that shall be your legacy—The gravity of your actions moving those around you.

You gain access to a new innate resource called Starscourge, which you generate with your own strength by converting the energy of your impacts.
While in your Supernova affected Rage, your body can hold a total amount of Starscourge Charges equal to your barbarian level, all charges are lost once that Rage ends.

You gain 1 charge of Starscourge for every hostile target that you have hit with your Cosmic Rage, Starbound Resilience, or initial use of your Supernova. 
These charges can be expended in the following ways: 

2 Charges — Cross Slash
Once per turn, when you take the attack action, you may make an additional attack with a second weapon you are holding in your other hand.

8 Charges — Gravity Well
Once per turn, when you use your Starbound Resilience you may use your Gravitonic Force as a free action as part of the aforementioned class feature first. Creatures moved this way are pulled into melee with you instead of only up to 10ft. closer. You may then move yourself and the previously targeted creature in a line to your chosen destination before the Starbound Resilience saving throw takes place instead. That creature takes 1d10 force damage for every 10ft. traveled this way. All creatures within a radius of 30ft. of that line are also caught within your Starbound Resilience. Disclaimer: Creatures make this saving throw only once per turn.

Cosmic Expansion
Once per turn, you may decide to expend any amount of Starscourge Charges. For every four charges expended, you extend your Supernova affected Rage by another round. Once the Rage ends, you incur one additional level of exhaustion per extended round in addition to the original level. You cannot be immune to, or ignore the effects of the additional levels of exhaustion incurred this way. (At 6 additional rounds this means death due to reaching the 6th level of exhaustion at the end of the rage.)