I have been experimenting with a Defensive build, and it doesn't seem to live up to any difference. Using a Conquerer with focus on stacking defensive to reduce damage taken, the mitigation is negligible. Probably because the attack revenge stack is by far more effective from what I assume are multipliers on the back end.
I feel it needs a bit of loving as a defensive player.
Revenge mode defense gives you a 31% reduction. Normal defense gives you 24% reduction. These are at max. Revenge mode attack however is completely different. You get a 96% increase in damage. It's the main reason people are complaining about revenge mode but most people don't know that little bit of info.