It's not that we can't kill it, we actually get passed that turn already, but we didn't bring a Summoner that time. That's why I asked here on what to do during that phase since it's pretty much a burst phase.

But since you told me that the DOT will pass on, I don't see any problem anymore. Probably won't use Contagion, it's better off to use in the boss instead since you won't maximize the remaining seconds of the DOT.

Anyway, thanks for the info.