Balrog or Balrogs were Maiar corrupted by Morgoth either before or after the creation of Arda. The Balrogs are great fire spirits, who cloak themselves in shadow and flame and carry whips and swords. Famed Balrogs included Gothmog, slain by Ecthelion, and Durin's  Bane, slain by Olorin(Gandalf).

Classification: Fallen Maia

Powers and Abilities: Superhuman physical characteristics, flight, regeneration (Low-Godly), immortality (Types 1, 3, and 4), shapeshifting, size alteration, elemental manipulation, fire manipulation, weather and lightning manipulation(Durin's Bane created a massive thunderstorm during his fight with Gandalf the Grey), magma manipulation, empathetic manipulation (The Ainur can create joy and by an extension, sorrow), transmutation, precognition, invulernability (The Ainur are immune from harm via conventional weaponry, as seen when, upon unlocking more of his divine power, Gandalf became invulnerable), resistance to death manipulation(In Lord of the Rings the land of the dead is a real tangible place, Mandos, and can be affected and exited. Ainur don't go there upon death, rather becoming spirits until the regenerate. The only way of keeping them there is if they are physically brought there and held by physical might)| intangibility and incorpearlity, reality warping, conceptual manipulation

Attack Potency: Small City Level (By successfully causing enough pain to Ungoliant that she was forced to flee, the Balrogs should scale above Morgoth's scream, which Ungoliant withstood point blank), likely higher(Morgoth's scream reached as far as Angband, however it is unknown if it's destructive power remained constant)|Universe level+(The Ainur exist outside of time and reality being completely unbound to Ea, initially viewing reality as a mere drama prior to their descent into it)

Speed: Supersonic+ to High Hypersonic, infinite when discarding their physical forms|Infinite(Without a physical form, the Ainur are said to be able to travel to whatever they want instantly)

Lifting Strength: Likely Class T(The Ainur shaped the world, including the mountains. In the Anulindale, Morgoth pulled down mountain ranges made by other Ainur, some of whom was possibly comparable to Balrogs)|Immeasurable

Striking Strength: Small City Level, likely higher|Universe level

Durability: Small City level+, likely higher|Universe level+

Stamina: Superhuman (The bodies of the Ainur are described as being akin to clothing which they can discard at will. Balrogs such as Durin's Bane have fought for days)|Limitless

Range: Extended melee range with swords and whips, unknown with other abilities|Universal+

Standard Equipment: Swords and whips

Intelligence: Unknown(As a member of the Ainur, the Balrogs should have considerable  knowledge of the world, and they have been repeatedly shown to be capable of matching skilled Elf-Lords in combat. However, their overall intelligence is unknown)|Possibly Nigh-Omniscient

Weakness: Water of sufficient volumes will douse their flames, though this is unknown if this has much effort on them beyond this|None notable