>Octopus blood contains thecopper-rich protein hemocyanin, which is more efficient than hemoglobin for oxygen transport at very low temperatures and low oxygen concentrations.
How does octopus blood benefit the octopus?

How efficient is hemocyanin rich blood, in say, -50°F?

Realistically, if I had an infinite budget, CRISPR and a truckload of octopi, how do we give a group of humans copper-based, hemocyanin rich, blue colored blood? What would be the effects of this blood in a human body?