TL;DR Game is stuck after the opponent activated an Explosive Runes (previously a Shifting Scroll) in Anomaly Mode
I was playing as Eudora against Sinclari in the Violet Hold (anomaly mode: all spells cost 2 less). On turn 5 I played a Vicious Fledgling, then killed my opponent’s Flamewalker with WANTED!. I used the Coin I got from WANTED! to play the (1) mana Explosive Runes (previously a Shifting Scroll). On the enemy’s turn, she Fireballed my Fledgling, then played a Kirin Tor Guard, which activated my Explosive Runes. The Guard died, but the game wouldn’t progress past that point.