Supergirl's second season has been all about aliens — or, specifically, the different types of rivalries, grudges, and discrimination between the DC universe's many different races of aliens, as well as the fear of aliens from humans on Earth. In the May 8 episode, the series is introducing another new race of aliens. The Phorians on Supergirl will be the next members of Planet Earth's collection of extraterrestrials. According to the CW, "When an alien attacks National City, Supergirl and the DEO learn the alien is a Phorian, an otherwise peaceful race with telekinetic powers." When they track down the Phorian, he appears to be a young child named Marcus, so the team decide to protect him after he bonds with James.
That description of the Phorian makes the idea of one attacking the city seem like an anomaly. In fact, I suspect the whole idea of blaming the Phorians for an attack might be part of Rhea and Lena's collaboration to scapegoat and deport all aliens, or at least contribute in some way to how the show has been making comparisons between aliens living in National City and immigrants living in the US in the current political climate. As Rhea's plans bring her closer and closer to taking over the planet, Kara and the rest of her crew will be forced to find a way to stick up for Marcus if he's innocent or understand why the Phorians attacked Earth if he's guilty.
Some of Supergirl's aliens are straight out of DC comics, like the Kryptonians, the Martians, and the Daxamites. But the Phorians are not from a planet within the DC Universe — and there's a lot of those. However, there are the similarly named Euphorians, a telekenetic and telepathic alien race who originated in a Green Lantern comic. The Euphorians are completely humanoid (besides their lack of pupils), they have a matriarchal society, and their longest-serving ruler was Kalista, a member of the extraterrestrial superhero team the Omega Men.
Given how badly the aliens have been treated on Supergirl Season 2 so far, it's possible that the Omega Men will take issue with Earth. In the comics, Kalista and the rest of the Euphorians fought in DC Comics event the Citadel War, where the Omega Men led a resistance effort against the Citadel, an empire that had enslaved lots of planets, including Euphorix.
So it looks like there's plenty of material that could be mined from the Euphorians to make Supergirl's Phorians an exciting addition to the show's ongoing alien storylines.