-Jonn has a VIDEO of what happened at the Artic base where he sees how the Parasite drains energy/lifeforce from people but when he and Supergirl first confront the merged creature they BOTH decide to go hand to hand with it??
I chalked that one up to over-confidence in their own invulnerability. I mean, Supergirl is invulnerable to lots of stuff that would destroy an ordinary human. Surely, she'll be immune to this infected human's powers, right?
Oops.