Judas Iscariotes is a one-person thrash and death metal project from Taquaritinga, São Paulo, Brazil, formed around 2020–2021. Operating as an independent, unsigned act with themes spanning horror, politics, and Satanism, the project has released a steady stream of material including Halloween (2021), Gore (2022), Bloody Pentagram (2022), and the EP Loaded To Kill... (2023), which includes a cover of Ratos de Porão's "Necropolítica" alongside original compositions.

Juggernaut are a thrash metal band from Blumenau, Santa Catarina, Brazil, founded in 2005 by guitarist Célio Jr after his departure from the local band Rhestus. The group blends aggressive thrash with progressive rock and metal influences, and their third full-length La Bestia (2021) — recorded with vocalist Cicero, bassist Valda, and drummer Alefer — tackled xenophobia and social issues across Latin America.

Juramento are a power metal band from Córdoba, Argentina, with a lineup that includes vocalist Adrian "Pirana" Gomez, guitarists Matias Villegas and Pablo Mancini, bassist Federico De Bernardi, and drummer Adolfo Diaz. The band released a demo presentation early in their career and have maintained an active presence in the Córdoba metal scene. They maintain an official website at juramentocba.com.ar.

Jun Sakuraba is a São Paulo-based guitarist, vocalist, and composer whose solo project blends neoclassical and symphonic power metal with Visual Kei and J-rock aesthetics, drawing inspiration from fantasy, gothic art, and video game music. Active since 2019, the project is documented on Bandcamp with releases including the single Black Rose Vampire, which pairs cinematic guitar melodies with a dark narrative tone.

Jupiterian are a sludge/death/doom metal band from São Paulo, Brazil, formed in 2013, known for crafting an oppressively heavy sound that fuses cavernous death doom with oozing, soul-crushing sludge. Their debut EP Archaic arrived in 2014, followed by the full-lengths Aphotic (2015) and Terraforming (2017), before they signed to Transcending Obscurity for Protosapien (2020), widely praised as their most focused and accomplished record.

Juramento are a power metal band from Córdoba, Argentina, with a lineup that includes vocalist Adrian "Pirana" Gomez, guitarists Matias Villegas and Pablo Mancini, bassist Federico De Bernardi, and drummer Adolfo Diaz. The band released a demo presentation early in their career and have maintained an active presence in the Córdoba metal scene. They maintain an official website at juramentocba.com.ar.

Justabeli are a death/black metal band from Diadema, São Paulo, Brazil, active since 2001, whose early work was rooted in brutal death metal before incorporating increasingly aggressive black metal elements. Their debut album Hell War (2008) was released through Impaled Records and earned them spots alongside acts such as Rotting Christ and Vulcano; subsequent releases include Cause the War Never Ends (2015), Intense Heavy Clash (2019), and Screaming Triumph (2023).

Jäger Miliz is a thrash metal band from Puerto Montt, Chile, formed in 2016 by members Jorge Trujillo, Fabian Soto, Martin Trujillo, and Miguel Yáñez. Their debut release, Demo MMXXI (2021), recorded and mixed at Supra Producciones, includes two original tracks alongside covers of Venom's 'Welcome to Hell' and 'Black Metal.'