BLM is a job of presence. You've constant damage but you're bound to turret mode to do so. When you're positioned the enemies have to be aware that if they get inside your are they will get Fire IV in their heads and sleeps too. The thing is that your allies have to work with this too. If they start chasing people that are running from you (the BLM) they'll make you powerless and eventually start losing damage output. At the same time, you as BLM must know how to change targets when someone flees instead of chasing back. Your base skill is a burst, changing targets oftenly is not bad.