DLC² stands for Diamond-Like-Carbon². Massive Blade DLC² Runners has the strongest type of coating Massive Blade offer. The hardness of the steel, together with this coating, will give you a perfect glide and sharper turns.
The black colored coating on the blades hardens the steel and creates a surface on the blades that are extremely resistant to corrosion. The coating improves the edge retention, and help the blades keep their edge longer. If you hit other blades, goalposts or other materials with the DLC² blades, you are less likely to get nicks on your blades compared to regular blades.
Massive Blades DLC² give an even better overall skating performance, with perfect glide with less effort. The turns will be more precise, and the blades will deliver a better response when you stop.
Although these runners are one of the best ones out there, it depends on playing style and personal preferences if these blades are the right ones for you.