The blue Lightning Crystal is an elite variant of the Laser Crystal enemy. It moves quickly in random directions and constantly shoots out short red lightning rails around itself.

Lightning Crystal attack

Turns red and fires several arcs of red lightning in your direction when approached. Lightning rails create an electrocution visual effect, but do not do damage in line with the animation. A single red lightning rail does 2 damage every other hit animation. The longer it's in contact with your character the more times it can do damage, up to 2 times. Currently lightning rails don't stack, which means even if you get hit with multiple lightning rails at the same time, you will only take 2-4 damage.