They both abandoned defense, only attacking each other with fierce force.
Black Dragon's Dragon Fist and Constandy's dragon body both produced afterimages. While they attacked with their fists, they also unleashed magic powerful enough to rival forbidden spells, compressing it to the extreme to avoid collateral damage.
Black Dragon compressed his black and crimson thunder into a tiny ball, even smaller than a human fist.
When struck in the abdomen by Constandy's Dragon Fist, Black Dragon, taking advantage of the momentum, spat out the compressed ball of black and crimson thunder. Constandy's dragon body was covered with layers of bright defensive arrays, but these multi-layered arrays were effortlessly pierced by the ball, striking Constandy directly in the chest.
Constandy was blown away by the impact, the dragon scales on his chest turning black.