I have a video of it but I don’t see where to attach it so I’ll describe what happened.
Essentially, I had a “Voidcaller” on the battlefield and the enemy had most of the game’s momentum. To swing the momentum, I used a “Twisted Nether” with the intention to wipe the board and summon a demon from my hand, the demon that was summoned was “Sargeras, the Destroyer.” Initially, I thought this was the perfect demon to turn the game around for me, but unfortunately, summoning him this way seemed to break the game. The board became stuck as a darker color, Sargeras’ portal failed to spawn, and none of his active skills would work. At first, I thought it was a client-sided error and that maybe my opponent could see the taunts I was supposed to have, but he couldn’t. So he ended up just swinging at me and winning the game.