Malekith possessed various superhuman attributes, some of which are common to his race.
Extended Longevity: Malekith, like all Dark Elves, possesses a greatly extended lifespan and ages at a much slower pace than humans. He is also immune to the effects of all known Earthly diseases and infections.
Regenerative Healing Factor: In spite his his body's increased durability, it is possible to injure him. However, Malekith's metabolism enables him to repair damaged bodily tissues much faster and more extensively than a human is capable of. The limits of Malekith's natural healing abilities aren't known, but it is believed that he isn't able to regenerate missing limbs or organs without magical assistance.
Magical Energy Manipulation: Malekith can manipulate great amounts of mystical energy for a number of purposes. Malekith has been known to often use his mysical powers to alter his shape and appearance.
Like all members of his race, Malekith has demonstrated a significant vulnerability to iron. For example, his mysical powers are useless against objects composed of iron. Also, being struck by an object made of iron, or even holding an iron object, can cause him great physical pain and injury whereas a similarly durable and powerful metal might cause him no discomfort at all.
Malekith is a Dark Elves who, along with his people, was destroyed by the Frost Giants ages ago. Loki released Malekith from the realm of the dead, so he would retrieve the ancient artifact known as the Casket of Ancient Winters.
In Norway, he was with the travelers searching something on the ruins of the Viking fort. However, when the others saw frozen figures, they ran and the other one was frozen while attempting to open the crate. Malekith then opened it and obtained the Casket of Ancient Winters. The Enchantress and the Executioner attempted to grab it from him, he froze them and unleashed the ancient winter on Earth, causing his dead people to rise.
Malekith returns as he claimed that he walked on both worlds of the living and the dead. He possesses the Asgardian artifact, the Casket of Ancient Winters that he unleashes on Earth to resurrect his dead people, create a new paradise for his people and cut of Midgard of the Nine Realms. But he was stopped by Iron, Thor, and Black Panther who came to stop him. He was destroyed by Thor's lightning strike conducted by Iron Man's armor and the Casket was sealed off for good.
Malekith is the cruel leader of the Dark Elves, a race of beings said to be older than the universe itself. Born into darkness, Malekith led his people in a war against the Asgardians, planning to use the Infinity Stone named the Aether to bring an end to the universe. But Bor, the King of Asgard, had it taken away from him. With their defeat inevitable, Malekith and the remaining Dark Elves escaped into space.
Years later, when Jane Foster was sucked into a vortex and the Aether entered her, Malekith reawakens and plots to claim the Aether to achieve his dark goals. To prepare his plans, he transforms his lieutenant, Algrim, into a Kursed. When Jane is taken to Asgard, Malekith and the Dark Elves immediately invade Asgard to get her and the Aether. During the attack, as the Dark Elves kill many Asgardians, Malekith and Algrim confront the Queen of Asgard, Frigga, who was protecting Jane. After fighting Frigga, Malekith attempts to capture Jane, but she is revealed to be a hologram. Enraged, Malekith demands Frigga to tell him where she is, and when Frigga refuses to do so, Algrim stabs Frigga, killing her. Thor, having witnessed the death, blasts lighting at Malekith, burning and scaring half of his face, and Malekith, Algrim and the Dark Elves flee Asgard and return to Svartaifheim.
Later, Thor, Jane and Loki travel to Svartaifheim to confront Malekith and the Dark Elves, intending to prevent them from causing more casualities and to destroy the Aether. There, Loki and Thor, using a hoax in which Loki appeared to betray Thor and offer to let the Dark Elves destroy Asgard, trick Malekith into drawing the Aether out of Jane. However, Thor's attempt to destroy the Aether fails, as it proved indestructable, allowing Malekith to absorb it. Malekith escapes, leaving Algrim and some of his Dark Elves to fight Thor and Loki, although Thor and Loki manage to kill Algrim and the Dark Elves (although Loki was seemingly killed by Algrim in the process).
Malekith, now activating his plan to destroy the entire universe, attacks Earth first by invading London. As he prepares to use the Aether to destroy Earth, Thor arrives on the scene and confronts Malekith. The two engage in a brutal fight that takes them through various dimensional portals. In the end, despite the fact the Aether cannot be destroyed, Thor manages to defeat Malekith by using Erik Selvig's devices to slice Malekith's arms off and stab his chest, before smashing Malekith into the wall of his ship, teleporting him back to Svartaifheim. Malekith's crumbing ship nearly falls on top of Thor and Jane, but Erik Selvig uses his devices to teleport the ship to Svartaifheim, where it falls on top of Malekith and crushes Malekith to death. The Aether is then taken by Volstagg and Sif, who give it to the Collector for safekeeping.
Malekith in The Avengers: Earth's Mightiest Heroes