It's not always easy to be a fan of the Legion of Super-Heroes, a once-prominent DC Comics property that, due to a series reboots and a changing marketplace, has been relegated to the fringes of the DC Universe. The signature sprawling cast, labyrinthine continuity and optimistic vision of the far-flung future apparently no longer hold the same appeal, leaving the Legion as something that needs to be "fixed." In its current state, the franchise is little more than a junked car, whose value is found in its individual parts -- Saturn Girl as an incongruity of DC's Rebirth, the villainous Emerald Empress in Suicide Squad, Phantom Girl in the Terrifics, and so on.

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Yet, The CW's Supergirl has long teased plans for the teenagers from the 31st century, dating back to the fleeting glimpse of a Legion Flight Ring in Season 1, and continuing with the introduction of Mon-El (played by Chris Wood) in Season 2 and Imra Ardeen (aka Saturn Girl, played by Amy Jackson) earlier this season. So, the promise of some iteration of the team in the upcoming midseason premiere, aptly titled "Legion of Superheroes" (not Super-Heroes, apparently), held such, well, promise. That is, until we got our first look at Brainiac-5 in an extended promo for the episode.

Brainiac 5 on Supergirl

Yes, that nightmare fuel is Jesse Rath (Defiance) as Brianiac-5, called upon by Chris Wood's Mon-El to help rescue Supergirl (Melissa Benoist) from a dreamlike state following her fight with Reign. Presumably the plan is to scare Kara awake, because Rath's Brainiac-5 may be the creepiest visitor since the Yellow Eyed Devil (aka the Shadow King) haunted the edges of FX's Legion.

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To his credit, Rath promised, "I get better looking throughout the episode," suggesting either an evolving appearance or a healthy dose of optimism. But Brainiac-5 shouldn't require either,

A product of DC Comics' Silver Age, Querl Dox is relatively straightforward: He's a blond-haired, green-skinned native of the planet Colu, who's inhabitants claimed to be descended from the Superman villain Brainiac. Blond hair, green skin; the ill-fitting purple jumpsuit and occasional little forehead "discs" are optional.

Brainiac-5

Supergirl goes all in on those glowing forehead discs, which is fine and perfectly "alien"; they've been part of the character's design from time to time, in comics and in animation. But it jettisoned the blond hair and green skin in favor of a white fright wig and teal makeup, presumably left over from the Andorians on the original Star Trek series.

This isn't a matter of entitled comic book fans grousing because a character doesn't look exactly as he does on the page, or that his costume is constructed with camera-friendly leather instead of unforgiving Spandex. This is just bad; nightmarish, even.

Look, the Arrowverse shows don't have lavish special effects budgets, which means viewers often have to squint and look past unconvincing cityscapes on "Crisis on Earth-X," or the cartoonish saber-toothed cat on Legends of Tomorrow. But they usually get the key characters right, with highly detailed costumes (and, OK, the occasionally clunky mask).

But blue-purple Brianiac-5, sitting there sipping his alien coffee, is enough to keep us awake at night.

Let's hope that Rath is right, and that the character improves throughout "Legion of Superheroes." "Just wait till I start talking," he assured. "I'll grow on you."

That's what we're afraid of.

Returning Monday, Jan. 15 at 8 p.m. ET/PT on The CW, Supergirl stars Melissa Benoist as the Girl of Steel, David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen, Chyler Leigh as Alex Danvers and Jeremy Jordan as Winn Schott, with appearances by Calista Flockhart as Cat Grant and Tyler Hoechlin as Superman.