Defiler and Bruiser combo at 70 is a very nasty duo if the defiler knows what he's doing. I've duo'd alot of stuff with a defiler as a Bruiser because he can let me get down to 30% hp (for 75% more crits) then just keep me warded between 20-30pct and I do double the dps I would normally do. I've tried duoing with other classes and they work well sure but so far I think Bruiser and Defiler duo is the best due to being able to ward at low life for maximum dps.