88. Proteus
FIRST APPEARANCE: UNCANNY X-MEN #125 (1979) Also known as Kevin MacTaggert, Proteus is the mutant son of Moira MacTaggert and the politician Joseph MacTaggert, the latter of whom forced Moira into a marriage, and then conceived by raping her. Kevin soon began to manifest energy-related powers that would eventually allow him to warp reality and even possess other people, as well as reduce objects to liquid, and even remove the powers from other mutants. Needless to say, he is one of the most fierce and powerful mutants in the Marvel universe, and nobody has been shown to adequately resist his possessive powers in particular. Proteus' most famous image is in the energy form pictured above on the right, though he is also extremely vulnerable to metal in this state, which can cause him sensory confusion and is generally regarded as his prime weakness. His consciousness can, in adverse circumstances, even dissipate entirely, requiring the assistance of other mutants to regain it.
87. Captain Cold
FIRST APPEARANCE: SHOWCASE #8 (1957) Captain Cold has been a persistent foe of The Flash, and has as a result become something of a fan favourite villain, taking on Silver-Age Flash Barry Allen, a simultaneous enemy and reluctant ally to Flash Wally West, and a killer of the fourth generation Flash, Bart Allen. Like many of the Rogues, Captain Cold relies on his various cold guns to inflict damage given that he has no innate abilities. However, his cold gun has a variety of nifty powers, such as freezing anything it hits, generating a "cold field" to slow down The Flash, making sheets of ice to trip enemies up and impaling enemies with stalagmites. In addition to this, he uses "ice grenades" to freeze everything in the radius. Though an inherently goofy villain, he's one of the few ice-based villains who can measure up to the inimitable Mr. Freeze, and in his newer iterations, has even developer super-powers that allow him to catch up to The Flash and kick his ass.
86. Mongul
FIRST APPEARANCE: DC COMICS PRESENTS #27 (1980) Created specifically as a villain to directly pose a challenge to Superman, Mongul, made his name during the Copper Age of comics, as not just stronger than Superman, but almost completely unable to be harmed. Though Superman
has bested Mongul in hand-t0-hand combat, it was at severe physical expense to himself, and in terms of out-Supermanning Superman, he is also able to teleport, while minor telepathic powers as well. Perhaps realising him
too powerful, the Modern Age Mongul was de-powered somewhat, and slowly grew to prominence while battling the Sinestro Corps and Yellow Lanterns. This lead to an anticipated stand-off with Supes, and though he put up an admirable fight, Superman's immense combination attack eventually put him down for the count (after demonstrating an incredible resilience, mind).