I'm well aware of what a BLU can do. It takes substantially less damage than any other melee DD from mob AOE attacks. That's being tanky while doing the most damage in the game, having aoe erase, having aoe cures and self hasting for 45%.

A moderately intelligent human being can wiki spell tooltips and descriptions. I'm not sure what you're arguing?

BLU literally takes much less damage than any DD, while doing the most DPS in the game for a melee DD(As stated by afania).

The job does too much and has no weakness. That is imbalanced.