Hoo boy, I'm sure finding myself dying a lot more stupidly than I normally do ever since I found this thread... Anywho, I was about to beat Ballos in around 4 minutes and 30 seconds with around 30-40ish health left when I screwed up boosting into his eye socket SUPER hard.
First, I boosted too high and ran out of invincibility frames.
After going down to the spikes for more frames, I boosted too close to Ballos, bouncing me away and into one of his eye orbs.
Getting desperate, I tried to just jump into the socket with the help of one of the eye orbs.
However, doing so forfeited enough health that by the time he had a sliver of health left, I ended up dying.
I swear, I haven't screwed up a boss fight THIS badly since... well... the Heavy Press, maybe?