Mystic Shadows released their debut CDr ...Over Old Hills in 2004, an eight-track record drawing on paganism, Norse mythology, and epic black metal traditions with a lineup of Myth, Arntor, and Falcon. Tracks like Into the Mist and Pagan Memories showcase the band's atmospheric ambition and folk-leaning sensibility, blending keyboard-driven grandeur with raw black metal aggression.

Mystical Fullmoon were a pagan black metal act whose output included the 1999 promo tape and the albums Beyond Somber Passages and Hermits Amidst the Marvels of Darkness, weaving occult and satanic themes into a raw, mid-paced black metal framework. The band drew on the South American underground tradition while incorporating the ceremonial atmosphere typical of European pagan black metal of the late nineties.

Mystical Vision play straight-ahead thrash metal rooted firmly in the old-school tradition, with their 2016 album Alchemy of Chaos showcasing tight, aggressive riffing driven by guitarists Carlos Mota and Silas Pimenta alongside the vocals and bass of Marcelo Sanches. A later release, A First Vision of Hell, continued the band's commitment to classic thrash sounds produced at GHM Studios in Manaus.

Formed in Salvador, Bahia, Brazil in 1989, Mystifier are one of the foundational acts of the Brazilian black metal underground. Their debut full-length Wicca (1992) and its follow-up Göetia (1993) established a ferocious and malignant sound steeped in occultism and anti-Christian themes, earning them widespread recognition in the international underground. After an eighteen-year gap between studio albums, Protogoni Mavri Magiki Dynasteia (2019) on Season of Mist marked a powerful return.

Formed in Salvador, Bahia in 1989 by Beelzeebubth, Lucifuge Rofocale, Behemoth, and Meugninousouan, Mystifier are one of the foundational names in the Brazilian extreme underground, blending primitive black metal brutality with a dark, ceremonial atmosphere and restrained synth use. Their run of records — Wicca (1992), Göetia (1993), The World Is So Good That Who Made It Does Not Live Here (1996), and Profanus (2001) — established them as the most significant black metal band from the northeast of the country.

Mythological Cold Towers deal in slow, heavy doom that draws equally from the death-doom tradition and epic doom's grandiose sweep, with lyrical themes orbiting ancient South American civilizations, mythology, and lost monuments. Albums like Immemorial (2011) and Monvmenta Antiqva (2015) display the band's ability to balance crushing heaviness with melodic keyboard passages and an almost archaeological sense of atmosphere.

Mábura is an instrumental psychedelic stoner/doom metal trio from Rio de Janeiro, Brazil, formed in 2019, known for fuzz-heavy riffs and ritualistic atmospheres. The band released the EP "Heni" in August 2020 and contributed the track "Bong of God" to the compilation "Doomed & Stoned: The Instrumentalists" (2021); they later collaborated with Lagarto Rei on the two-song instrumental EP "Abyssopelagic."

Mães Morrendo is a doom metal project from São Paulo, Brazil, founded in 2019 as a solo endeavour by multi-instrumentalist Melissa Ângela, who also performs with Dirty Grave and the psychedelic doom band Melissa. The project blends doom metal with sludge, grunge, and rap influences, building a catalogue that includes releases such as "Corrosivo", "Hemorragia Social", and "Água-viva". By 2024 the project had expanded into a full power-trio lineup with Neli on drums and Bárbara Guieiro on bass.

Mërgim is a Buenos Aires sludge/post-metal trio consisting of Gustavo Cirigliano on guitar, Sebastián Manino on bass, and Nicolás Melichar on drums. They released their debut album Shpirti in March 2020, recorded at Estudio Instituto TAMABA, followed by the five-track record I in July 2022, produced with Martín Gandulfo at Estudio Paraíso.