Methrasheros is a thrash/punk crossover band from Ramos Mejía in the Buenos Aires province, featuring vocalist Pablo Methrashero, guitarists Julio Pursan and Gabi Asko, bassist/vocalist Hernan Wattusi, and drummer Leandro Lapolla. Their eleven-track album Enemigos was released on October 6, 2018, with tracks addressing political and social themes.

One of Rio de Janeiro's earliest thrash metal outfits, Metralion emerged in 1986 with sharp socially critical lyrics and released their debut album Quo Vadis in 1988, followed by the EP A Mosh in Brazil in 1989. After a long dormancy, both early records were reissued on CD by China's Awakening Records in 2019, reigniting interest that led to the comeback full-length Requiem for a Society in 2021.

Metralleta is a heavy/groove metal band from Larroque, Entre Ríos, a small city in eastern Argentina seldom represented in the local metal scene. Their recorded output includes the 2009 album Todo o Nada and the follow-up Puente, released on August 1, 2014, which features tracks such as "Cuando los muertos viven," "Vértigo," and "Victoria."

Metralleta is a heavy/groove metal band from Larroque, Entre Ríos, a small city in eastern Argentina seldom represented in the local metal scene. Their recorded output includes the 2009 album Todo o Nada and the follow-up Puente, released on August 1, 2014, which features tracks such as "Cuando los muertos viven," "Vértigo," and "Victoria."

Metáfora were a thrash/death metal band from Sergipe whose releases included the album 'Paganini' and the later full-length 'Vincit Omnia,' both catalogued on Metal Archives. The band split up after cultivating an aggressive sound rooted in the Brazilian extreme metal tradition before dissolving.

Mezexis is a Chilean black metal band that plays raw, stripped-down black metal characterized by simple riffs, basic drums, and rough reverb-drenched vocals. The band released their debut Demo I in 2022 as a self-released cassette, a two-track recording clocking in at just over seven minutes.

Miasthenia weave melodic black metal with deep roots in pre-Columbian mythology and indigenous resistance, singing entirely in Portuguese about Aztec, Maya, and other native Amerindian cosmologies. Their fifth album Antípodas (2017) was widely praised by the Brazilian metal press and built on a catalogue stretching back through Legados do Inframundo (2014), Supremacia Ancestral (2008), and two earlier records on Somber Music.

Michel Garrido is a Santiago-based musician best known as the longtime lead guitarist of Chilean extreme metal band Necrodead. His solo work blends rock, post-metal, and folk influences, with releases including his debut album Bahual (2009) and the Australis Records-distributed Güiña (2021), the latter recorded across studios in Chile and Argentina during the country's social unrest and the COVID-19 pandemic.

Mictian play a heavy death/doom blend rooted in the dark, mournful tradition of Black Sabbath and carried forward by three brothers who formed the group after their previous cover band dissolved. They documented their early sound on the demo CDs Hallucination (2005) and Lost in My Sick Mind (2010), and appeared on the Brazilian compilation Doomed Serenades Volume 2 in 2015.