Not sure about world first as I dont know how to check the millions of others' achievements, however I will say I agree the levitate buff is kind of a "smart use of mechanics" type cheese and wasnt too happy about it when I found out it was possible, but after multiple attempts sub 5% while jumping over lasers I figured the few globals I had to jump out of his melee range to avoid the lasers were the few globals it would take to kill him and caved in. I hope it gets fixed (since casters can literally stand in the one safe spot the entire fight and never have to move?) but I also hope it doesnt get fixed until they make the bugged "invisible energy balls"....visible.
Either way, looking forward to season2 Brawlers! Oh and thank you =)