This is to demonstrate how certain characters would fare against others from their universe. 

Challenger

Higher or same level characters he could defeat

  VS   Winner 

Night Storm draws her power from the star closest to her. If Roguestar were to fight her in her current star system, The Eta Carinae system, Night Storm may come out the winner. That system comprises two blue stars that greatly amplify Night Storm's power, but that power diminishes the further she is from her system. If Roguestar fought her in some remote part, he would withstand Night Storm's Sunburst and would overwhelm her physically. 


  VS     Winner  

Roguestar's Nova Blast would be ineffective against her. Although the blast is mainly a physical attack, it is also made up of energy and Hartree would easily diffuse its potency. She could retaliate with energy attacks, but Roguestar is highly resistant to these, so the battle would be a physical one, where the advantage would be Roguestar's. Still, Hartree could potentially drain his own vital energy and take the upper hand.


Characters he would not beat

  VS     Winner  

Meridian and Roguestar have had their share of mock battles and although all of these were for sheer fun, Roguestar knows for certainty that Meridian would win against him in a battle to the death. His concussion blasts could slow her down a little, but they would never overwhelm her. As for his Nova Blast, she has taken it full force many times. 


  VS     Winner    

Geomass would win because Roguestar could never use enough force to topple the giant unless he used his Nova Blast. Still, Geomass could raise up a rocky protection to diminish the force of the attack. After his Nova Blast, Roguestar would be in recharge mode, which would give Geomass plenty of time to physically restrain him.