What champions have people forgotten are terrifying when they're strong?

Some examples: Wukong - Eliminates ADC off the face of the planet, turns around and sets up the 5v4 engage for his team Maokai - Actually unkillable late game Quinn - Every Top Laner fighting her sighs dramatically, followed by the rest of their team in about 5 minutes

There's a good handful of champions who are so weak and/or niche that the community basically pays no attention to them. However, if they ever did get back into the game, they'd quickly become overbearing nightmares. What champs do you think fit that criteria?