Ey, this is pretty epic.
The only problem IMO is the misuse of basses.
If you listen to Virtual Riot, (probably the best dubstep producer in the game right now) you'll notice his patterns often include a certain formation of basses, such as in Pray for Riddim, or Cry some more. He likes to have a low growl, high bass, medium pitched bass, slightly lower bass, fill growl, start over. I'm not saying you should copy this pattern exactly but I am saying you should work on adding some dynamic and pitch and frequency range to your dubstep. For instance, use lots of Flange and comb filters in serum or whatever plugin this is, and overall put lots of variation in your basses while keeping a pattern that makes sense.
Oh, one more thing.
I know this is a WIP, but the effect of the buildup isn't as good without some weird shitty high-pitched basses and risers. Just an opinion though.
Songs to notice bass patterns in:
Pray for Riddim (Virtual Riot)
Shindeiru (Virtual Riot)
Cry Some More (Virtual Riot)
Dog Fight (Virtual Riot)
Degenerates (Virtual Riot)
Warriors of the Night (Virtual Riot + Datsik) This one is particularly interesting at 2:32 here: https://www.youtube.com/watch?v=FqxWTJhBMyQ
Just some thoughts, nice job getting into the dubstep game man. Welcome to hours of trying to design a bass that sounds like a crying baby xD