The Guardian and Parasite are both featured in official photos promoting the Supergirl episode "Changing."
Official CW description for the Supergirl episode "Changing"
The first photo of Mehcad Brooks in costume as the Guardian in Supergirl Season 2 has been revealed.
James Olsen will become the vigilante "Guardian" in Supergirl Season 2.
Dean Cain returns to Supergirl in Episode 17 "Manhunter," and it seems The Guardian might be involved too....
The Smallville Season 11 story arc Guardian will be collected in April.