The Flash: 8 Best Villains

It's been a minute since we've seen Mark "Weather Wizard" Mardon, but he's remained one of Team Flash's more memorable minor threats. Last we saw him, he and The Trickster were taken into custody after their Christmas shenanigans were foiled back in season two, and he hasn't been seen since.

He has a vendetta against Joe West, who he blames for the death of his brother, nearly succeeded in destroying Central City with a tsunami that forced Barry to test the limits of his abilities all the way back in the first season, and has a relatively level head that makes his calculated brand of evil all the more dangerous. Since his last appearance, The Flash has faced off with a whole bunch of new enemies, but Mardon's ongoing absence has been missed, as few of them have the level of connection that the weather-changing antagonist has to the team as someone that's been around since the early days.

With Leonard Snart no longer around to form the Rogues, Mardon would be a great option to take his place were he to return, as the concept of lower-tier antagonists banding together seems to have been abandoned when Snart shifted over to Legends of Tomorrow. He's proven hot-headed and mean, but his awareness that his far more ruthless brother's actions aren't forgivable suggest that he's not totally beyond redemption, positioning this memorable antagonist for an even bigger future if and when he resurfaces.