Just before the tank pulled the third boss, Liu Flameheart, the healer left the group. The tank lasted for about half the fight, but ran out of cooldowns. I was already hovering over the growl button and right clicked the moment the tank died. Unfortunately, everyone else in the party was dead at that point. For half a second, I hesitated, debating feigning; the boss still had around 800k-1M hp left. But I decided to give it a shot anyway.
Ursa tanked beautifully! His health didn't spike too much until the very end, when he died, but I just heart of the phoenixed him back up and he taunted right back off me. Boom, dead boss. Boom, she dropped a gun!
Soooooo, yeah. I like this.