I like how fast and fluid Nin is.
It's speed let's me greed.
Ration and Hyosho Ranryu let me keep up the pressure when the boss thinks it can make me disengage.
Before Nin I enjoyed jobs that did more stable and consistent damage. Not the peaks and valleys of burst windows. But Nin showed me how fun it can be to try and move things around to get that damage right where you want it.

Plus, it's glam game is sick, even if a lot of their knives are rather overly designed for me.