Game breaking? Even before the removal of Double Dark arts, it already had lower damage than WAR while being unable to sustain it for all but a short period of time. After the removal, not only is our damage now considerably lower, but our sustain hasn't changed at all, leaving us likely to be the worst DPS of the tanks over the period of a fight.
But that's not even close to what matters most. What matters most is our mediocrity as a main tank, while completely lacking utility and value as an off tank.
We don't survive as well as the other tanks, we don't support as well as the other tanks, we don't even do damage as well as the other tanks. What do we do?