The main antagonist of LOST. Stating any more would be intense spoilers.
Powers and Stats
Tier: At least 9-B, possibly High 6-C | 10-B, 9-C with weapons
Name: The Smoke Monster, The Man in Black, DHARMA initiative calls him Cerberus, Jacob calls him brother, the security system, not John Locke
Gender: Male (Occasionally appears as female)
Age: Consciousness is 2,000 years old. Physically 43 in his original body. Physically 48 while impersonating as Locke.
Classification: Formerly human; Monster; Evil Incarnate
Powers and Abilities: Levitation, Intangibility, Dream Manipulation and Manifestation, Immortality (type 1), Shapeshifting (Mostly dead people. Medusa spiders and Walt are exceptions) and implied mind reading (He would have to know who people like Christian Shepherd are to transform into them, so he would've had to read either Jack's or the deceased Christian's (it's possible in the show) mind), Paralyzing venom (as Medusa spiders), superhuman strength, Precognition (knew the events on the sub, that Locke was going to die, and the crash of flight 316), Electromagnetic manipulation, Necromancy | His adoptive mother has fans speculate that he has powers even pre-death
Attack Potency: At least Wall level (Has crashed through trees and walls), possibly Large Island level (Powered by the Heart of the Island. His escape from the island would be the end of all things good.) | Human level, Street level with a weapon
Speed: Peak Human
Lifting Strength: Above average human (Overpowered Eko)
Striking Strength: Wall Class (Didn't one-shot Eko, but still casually destroys walls) | Human Class
Durability: Likely Island level (Nothing in its own verse has been able to hurt it in the Smoke Monster form, just repel it. This includes a nuke.) | Human level
Range: A few kilometers (should be this large) | Average human range
Standard Equipment: None notable.
Intelligence: Extremely high. He has thousands of years of experience and is a master manipulator. His powers of persuasion was present from the beginning of the show. Found a loophole into killing Jacob, as he is not allowed to do that himself. Turned long time protagonists onto his side.
Weaknesses: Sonar fences, ash circles, and explosives can repel him, but will not harm him whatsoever. Bunyan trees may also fit this category. He cannot directly harm Jacob, his brother. Candidates. | Normal human weaknesses (was killed by being shot and kicked off a cliff)
Key: As the monster | Pre-death/Regaining Mortality