Kylo Ren showed off a lot in Star Wars 7: The Force Awakens. When we went into the movie not much was known about how power he is, why is lightsaber looked like that or his familial ties into the Star Wars universe if any.
Kylo is going to prove in Episode VIII that he's even more powerful and badass. He proved to be a badass in Episode VII, but some fans had problems with him. With that being he was so powerful, but lost to Rey and Finn. Many people didn't realize that he was wounded in that battle so he had the odds stack against him.
Ren has proved in Episode VII that he is a force to be reckoned with, pun intended. He also proved that has what it takes to stack up against Vader and possible be a better Star Wars villain than Vader was.
For those who don't know Spoilers are approaching
Ren proved his strength with the force pretty early in the movie with freezing a blaster shot and Poe in midair. A lot of people probably went insane hearing that because some of the greatest Jedi and Sith could not do that. Not even Master Yoda could. It show viewers of the movie that Kylo was going be very strong with the force on a scale we've yet to see before.
Another thing was Kylo was so powerful with the Force that he take a shot from Chewbacca's bow-caster and survives. He then pursues Rey and Finn after they try to escape.
One of the biggest things about Kylo is he did what Vader could not. Vader could not kill his son Luke and that ultimately brought his redemption to the light side. Kylo proves that he does not want to follow in his footsteps there and kills his father Han Solo. This ties into what was previously stated with Chewie and the bow-caster.
Then Kylo Ren has a similar look to Vader with the black suit and helmet. Except Vader needs his to survive and Ren uses it to look stylish and I can't blame him it's a nice suit. That put aside Kylo takes of his helmet on the Starkiller ship and ends up leaving it when he is evacuated off after Finn and company destroys it, but don't worry he gets a nasty scar on his face that may show he doesn't need the mask after all.