I'm having difficulty figuring out what you need to do in order to complete the clear Lord of Light mission using only a certain character class - I managed it twice yesterday on Gunner but then it reset to 0 on my third try. Today I tried again on Assassin using only gunners from the start 3 times - this gave me the first tier completion but, again, says I have completed 0/3 for the second tier. Are there any additional requirements? Do I need to fill all the Eddie slots for example?