I am curious at this and I'm sorry that I missed the video before it got hanged
Ignore anyone who says it was like Blaze singing the Trooper, it's literally the
opposite of that.
Blaze could hit high notes here and there, but songs like The Trooper required him to sing the entire thing outside of his range. Constantly having to reach for notes he simply couldn't perform in a sustainable way regularly. Which is
exactly what Bruce has to do in the second half of Aces High's verses
when he is not sick.
So, instead of straining even more and risking blowing out his voice due to being sick, Bruce stayed in his mid and low range and changed the vocal lines. This obviously sounded very differently to the studio version, but he sounded absolutely phenomenal, due to still having great control over his voice in the lower registers, despite being sick. It's a bit like a lot of the sections on Senjutsu (notably large parts of Lost In A Lost World for example), where he sings extended periods without the air ride siren.
For the chorus he chose to let the crowd sing a couple of lines and for the rest sang lower harmonies, while sounding phenomenal.
Again: Not a single person has explained how him sounding more relaxed and singing everything in key translates to him sounding "horrible", especially when he genuinely sounds tortured when trying to sing the song the regular way when he's healthy.
That is when he sounds like Blaze; not when he alters the melodies to accomodate his currently diminished range.
Hopefully someone will reupload the video so that you can listen to it and form your opinion, but I hope you approach it with an open mind. Just because it's not identical to the studio version doesn't mean it was bad.