This would only come into play when there are just one or both tanks left alive, and the boss just does away with them after 10-12 seconds?

I'm not sure if anyone else feels my frustration with tanks holding players hostage because the boss can't kill them if they know the mechanics, and they also can't kill the boss because it has too much HP remaining. This came to mind with the last Rubicante EX party I was in, and would have loved it if he just kept spamming Dualfire until naught but ash remained.

Thoughts?