Mortiço is a one-man black metal project helmed by Andrew Gargula, who recorded the debut album Cumming in your Guts at Home Estúdio Mortal Ways in Rio Claro between January and May 2021. The same year Gargula released a split titled Tempos de Cavalaria alongside Far From Everything, keeping the project active in the tape and digital underground from its first months of existence.

Mortumbra is a four-piece black metal band from Osorno in southern Chile, describing themselves as "bards and minstrels devoted to dark and forgotten arts." They released their debut recording, PROMO MMXXV, in February 2025.

Mortuo is a one-man black metal project from Curitiba helmed by Vox Morbidus, who also operates several other underground solo ventures. The project draws on second and third wave black metal traditions, blending high-pitched vocals with keyboard textures over mid-to-fast tempos, and released the album "Old Memories of the Past" through Tornhate Records.

Mortuorum was a raw black metal band from Mauá that operated with an uncompromising anti-religious stance and a prolific underground output. The project released a string of short, aggressive recordings including "Marked for Death" (2021) and "Mortuorum III" (2022) before going silent.

Mournful Tears are a black metal act from Guarujá whose lyrical world blends dark poetry, occultism, and metaphorical inner journeys. The band has released material through Occult Moon Records and appeared on a split alongside fellow black metal act Black Angel.

Movarbru are a long-running Satanic black metal band from Sapiranga, Rio Grande do Sul, whose sound draws from the raw South American underground tradition. Their 2020 EP 'Sob o Domínio do Antigo Culto,' recorded at From Hellcords Studios in Porto Alegre, was released as a 300-copy limited edition through Cianeto Discos and features the band's core themes of occultism and anti-Christian fury.

Mudrost is a black metal solo project by Hellsgaard, born in Curitiba in 2022 and prolific from the start. The project released "Melancholy State of Soul" in August 2022 and followed it with "Sanctum Regnvm" in January 2023, establishing a cold, uncompromising sound rooted in orthodox black metal traditions.

Mulmeyun is a Santiago-based extreme metal project blending symphonic, black, and gothic doom elements, with the project's first release, the two-track EP A Tale of Love, appearing in September 2018. The band uses a Vocaloid voice bank as vocalist, an unusual choice within the Chilean metal underground, and has released a steady stream of material including Struggle (2020) and An Ancient Calling (2021). Thematically, the project frames suffering and sacrifice as necessary responses to modern nihilism and existential despair.

Munkill is an extreme metal band from San Carlos de Bariloche, Río Negro, whose founding members include vocalist/guitarist Demogorgon Malignum, bassist Malice Misanthropic, and drummer Sebastian Ortega. Their debut album "Suicide Or Homicide" was recorded at Insight Producciones and released in September 2012, followed by "Ambition and Destruction" in 2020, recorded in quarantine and mixed by Agustin Ortega at Demogorgon Malignum Producciones.