The Monk Temple

[Mishaela]

I disagree. You should be using fracture on every boss encounter in the game. The ones that make you go dry you just have to know when during the fight to stop using it so you don't go dry.

There are many targets/phases where Fracture is not a good skill to be using because of the high TP cost or because of preserving GL stacks. However, as is the case with Touch of Death, it's a good skill to toss on anything that's going to soak its duration when you can afford the TP. Places where I find it is useful to have include:
Primals, to DPS while you or the target is moving.
Turn 2 ADS because you should have plenty of TP.
Turn 4 on dreadnaughts maybe, pending your group's DPS.
Turn 5 on Twintania in final two phases since it gives you some damage while you are moving around for twisters/dreadknights/fireballs.
CT bosses like King Behemoth and Acheron, toss it on with your other DoTs before hiding for meteor/flare.