So I've cleared Brayflox HM with a number of parties to date. Almost every one has been speed runs. But a similar problem seems to arise for me every time I run that dungeon. During the final boss, as a SMN I have a TERRIBLY hard time helping to push back bombs at any sort of decent rate. I don't know if it's my cast time, or what seems to be the problem. My instinct is to just spam Ruin at the bombs at least one time to push it back. The problem is during my cast time, someone else will generally run in and push back the bomb I was targeting, thus forcing me to change targets, and start casting all over again.

So my question is this: what's my best way to clear bombs in Brayflox HM's final boss as a SMN?

As always, any and all help is greatly appreciated!