I just played through Sol Badguy's arcade mode in Guilty Gear Xrd Revelator. I didn't quite understand everything that was going on, since this is my first Guilty Gear game (I have no idea who Aria is (I'm assuming Sol's dead love interest or family member), though I know enough about anime tropes to figure that Sol and That Man/Raven are normally enemies, but they're forced to work together because the idea of Justice being revived threatens the world), but from the gameplay, I could see Sol Badguy working in Smash.
One question about his playstyle - is he normally not supposed to have much range? Even on Beginner difficulty, there were some opponents (Axl, Sin, I-No) who could send him flying to the back to the stage and spam attacks that cover the length of the entire screen to keep him there, with seemingly nothing he could do to counter. I won the matches (mostly because the AI wasn't TOO bad about spamming it, though there were still a few rounds where I came close or one where I lost), but I don't know how you're supposed to deal with that on higher difficulties and I could see it being extremely frustrating.