Arrowverse: The 'Big Bads' Of Every Season - Ranked
2. Reverse-Flash
Season 1 of The Flash remains the greatest season in the Arrowverse continuity in my eyes, and that's down to this guy right here.
The opposite of Barry Allen in every way ('Some would say... the Reverse'), Eobard Thawne is the Flash's greatest rival. It doesn't matter that his backstory makes your brain hurt - what matters is that every time Reverse-Flash is on screen, whoever is playing the role, you're going to have a good time.
Tom Cavanagh was the stand out performer of The Flash's first season, as Reverse-Flash went undercover as Harrison Wells, bringing a creepy sort of humanity to the character, while Matt Letscher has absolutely made the role his own in later seasons, now that the character is free of his disguise and able to showcase his abilities.
Thawne is currently travelling through time with Damien Darhk and Malcolm Merlyn, but his complete obsession with the Flash will always bring them back together.