Use this spell. A vast majority of people who whine about having to level NIN to 37 aren't using Kurayami. I don't care if you have a RDM on hand who can cast blind for you, YOU do it yourself for the enmity boost, as soon as the mob is being pulled and is in range of casting. This spell alone put me over the top and allowed me to solo tank Yhoator Mandragora, which was something I would have never imagined possible as a NIN.
Also noteworthy, with Hojo/slow/Sprout Smack/etc. on a mob, you should have enough time to recast Ichi between swings. Try to guesstimate about when the mob will attack, and start casting Ichi a split second before it. Very useful for solo tanking rather than just relying on a mob to miss to get Utsusemi up. Do it right and I'll bet money your party will be impressed, and your party leader will keep your name in mind for the next time around too.