I exploded after triggering a response to Blue Sun's twlight by sacrificing my Cathar Commando in response not to be copied by Blue Sun. I targeted one of my artifact creature and when it resolved I exploded. Very frutrating as I was leading 1-1 and 20 to 3 on third BO3, and was going lethal in the next turn.
Then as a result I dropped to Platinum 2 instead of being back to one win to go to Diamond 4.