For the Assassin, don't go with his "Shadow Move" skill over lvl 25, it tends to glitch as many commented before, lvl 25 is OK, I personally tested it, but around 26-30 it will glitch sooner or latter. Why? Easy, the teleport thing. It glitch the character and make him to go around the portal again and again. Seems some bad coding when the dev make him to tp to the nearest enemy. Still a good character to have all the 5, specially if you max his other skill, Poison, and his crit chance and attack % are good too, also he can dual wield weapons (equip him with dual De Corbin, the version with health and damage % buffs, he do a lot of damage)