I once read a topic saying that it's impossible to get perfect 15 blood stone in a arena match.
Then I played some arena and the match up is someone much higher than me. My point is 2044 while his is 2100.(most likely will lose)
Interesting enough, I let it run auto(since I think I will lose) and the result surprised me.
I never thought it's possible also. But here you go. +15 stone and I will say i only saw it once which is today.