So the mask could be interpreted as a tool that's allowed this affect/control for calling on the octopus? He'd try to get closer, despite the blight risks, but y'know. Knowledge.

Second fight: Aside from the crystal radiating, is any of the Dark energy being pulled for use, or having other kinds of energy drawn into it?

The joke question would be if Judar could eventually absorb the crystal's dark energy, but that might be a legit question down the line depending on things.