Synergies is a full conversion and balance mod for Torchlight 2 that was ranked as one of the 15 most brutal (hard) mods of all time by PCgamer recently Currently contains two finished classes, the Warlock and Necromancer, and many many more changes!
A smallish demonstration of the class "Ninja". Note that my PJ is only level 10 and so I have few skill to use. Anyway, this is still work in progress. Remains to be done and to test. They need to create more skills and balance the PJ.
The detail of the Ninja class you can see on: Forums.synergiesmod.com
Right there you will find information on how to add it to your TorchLight 2 if you want to try the Ninja.