Originally Posted by
Nominous
It gets weird if you have Sen in a dungeon before the boss is pulled. Once you get Hagakure, you can just use that to wipe your Sen clean before the pull. If you don't... It gets stickier.
Once your rotation starts, you want to avoid overlapping any Sen already gained. If you're doing your rotation perfectly, you never will. If you find yourself in an unfortunate situation where you don't have Hagakure, and you have no buffs (but you DO have the corresponding Sen), you have one of two options. Overlap Sen is option one. Or you do Hakaze>buff (insert Shifu or Jinpu)>Iaijutsu>ender. That way, you aren't overlapping Sen, because you're consuming it to cast an Iaijutsu first.