I really like this idea, however I'm not too fond of the reward.

Maybe if there were multiple of these tasks, with some being extremely challenging? For example: kill Jad 5 times. Every task will each give one task point. There would be a high amount of tasks (100+), each giving the same reward (maybe some sort of untradeable mystery award such as a casket (hard) which could give all sorts of items at a very low rate). Once completing every task, you'll be rewarded with a cape (forgot the name) which will have slightly higher bonuses than a maxed cape.

Thoughts?