I love James Rolfe. I've been a fan of him since he was the Angry Nintendo Nerd, with only 3 videos under his belt.
As for my input, I would have suggested having a legitimately tough Belmont opponent (possibly mind-controlled or similar to Soma's circumstances) since Richter always felt like an incredible push-over coupled with the fact that you AREN'T supposed to fight him, making Soleiyu one of the only Belmont opponents you have to duke it out with. But then Julius popped up in AoS and fulfilled that desire.
I still don't want to leave this thread empty-handed, so let me think. If it were up to me, I'd love to see more "team" boss fights, like Stella & Loretta in PoR (which AGAIN you aren't supposed to fight!!) Dracula and Death (again in PoR), the three doppelgangers from SotN, and even as far back as the dual mummies in the original Castlevania. CotM had a dual dragon boss fight too. So they definitely exist, but I just wish they were used more. There's a distinct element of danger in having 2 (or more) different opponents to fight at the same time.