Asfixia is a thrash metal band from Campinas, São Paulo, one of Brazil's most active metal cities outside the capital. The band operates in the old-school thrash tradition, drawing on the deep legacy of the Campinas and São Paulo underground scenes that have produced dozens of aggressive thrash acts since the mid-1980s.

AshBürn is a power metal band from Vitória, Espírito Santo, formed around 2014–2015 and led by vocalist Heron Ribeiro. The band released the album "You Can Not Kill What Can Never Die" in 2020, recorded and produced by Thiago Bianchi at Fusão VM&T Studios in São Paulo, and has shared stages with established Brazilian metal acts including Almah (featuring ex-Angra vocalist Edu Falaschi) and Noturnall.

Ashes of Mirra is a progressive metal band from Rio de Janeiro, formed in 2023, featuring vocalist Weslen Amorim, guitarists Fabio and Sebastian Garcia, and bassist Roberto Ribeiro. The band released their early material on Bandcamp, with tracks including "The Pangea Puzzle," "Limit," and "Speechless," pointing toward a sound that favors compositional depth within the progressive metal tradition.

Ashriel is a one-person Atmospheric Black Metal project from Bogotá, Colombia, active since 2016 with a hiatus between 2018 and 2020. The project released the demo Spectris in 2016 and the single Memories Rises from Dead River in 2018, exploring themes of death, emotions, personal struggles, and nature.

Ashtar was a progressive folk metal band from Rio de Janeiro that blended Celtic folk melodies, violin, and clean female vocals with a doom-inflected metal foundation. Originally formed in 1997 and known for their 2002 debut album Urantia — a record shaped by esoteric and Irish/Scottish lyrical themes — the project went through multiple lineup changes before dissolving in 2015.

Ashtoreth is a doom/black metal band from Florianópolis, Santa Catarina, whose music is steeped in the mythology and folklore of the city known as the "island of magic." Their 2022 debut album Bruxólico — released on Dejeto Sonoro Records — weaves distorted guitars, unconventional percussion including a zither, and varied vocal approaches into six tracks across 40 minutes, drawing on local witchcraft legends and the poetry of Symbolist writer João da Cruz e Sousa. The album is envisioned as the first part of a trilogy.

Asilo was a Buenos Aires sludge, drone, and doom metal collective that built a catalog of slow, crushing releases across the 2010s, including the split with Neh Czneg (2013), Comunión (2014), and Desintegración (2019). Their approach leaned toward extended, corrosive compositions that placed them firmly within the heavier end of Argentina's underground doom scene.

Askaroth is a black metal trio from Isla de Maipo, Chile, featuring Odal (bass, vocals), Cruelbuth (guitar), and drummer Nilsson Arriagada (also known as Beleth), who have been active since the early 2010s with releases including the demo "Unholy Demian" (2011), the cassette "Lejania" (2012), and a split with Nocturnal Delirium titled "Memories" (2012) through Depressive Illusions Records. The band issued a self-titled full-length album in March 2022.

Aske is a black/death metal band from São Carlos, São Paulo state, operating in the Brazilian extreme metal underground since 2018. Their approach sits firmly in the raw, aggressive end of the black-death spectrum, with releases distributed independently through Bandcamp.