[13] In November 2012 Obsidian Kingdom released the LP Mantiis, a concept album consisting of a single song divided into 14 tracks, which is defined by reflecting a diverse palette of emotions[14] and the great amount of genres that it contains.

[15] The album, that includes guest appearances by Fiar (singer from the Catalan black metal band Foscor) and trumpeter Nicholas Dominic Talvola, obtained very positive reviews from specialized press.

[16][17][18] Once more, design was in charge of Ritxi Ostáriz, who posed this time as Art Director, while creative responsibilities relied on visual artist Elena Gallen.

[21] In November 2013, the band released Torn & Burnt, which contains seven remixes from Mantiis signed by electronic producers such as DJ Oktopus from Dälek, Subheim, Poordream, Necro Deathmort, Jr Morgue, Drumcorps, Larvae and Mothboy.

[30] Shortly thereafter, the band announced a new line-up (with two new members Seerborn Ape Tot on guitars and Om Rex Orale on bass) and the recording of their new album in the Fall of 2015 with the London-based Colombian producer Jaime Gomez Arellano (Ulver, Paradise Lost).

[4] It features the guest appearances of Kristoffer Rygg in "10th April" and Attila Csihar in "The Kandinsky Group"[5] and the artwork design is once more credited to Ritxi Ostáriz[39] and Elena Gallen.

[46] In June 2018, Obsidian Kingdom received a commission from the Centre de Cultura Contemporània de Barcelona to write an original score for the classic silent film The Phantom Carriage, to be performed as the opening for the Gandules'18 "Illuminated cinema: Magic, altered states and the occult" open air cinema cycle, which was part of an exhibition dedicated to the occult called "La Llum Negra" (The Black Light).

[48] In December 2019, the band performed two new songs for the first time at the Madrid is the Dark Fest, displaying another line-up change: Jade Riot Cul on the keyboards and Eaten Roll I no longer on guitar.

[59] The album was noted for its variety,[60] unpredictability[61] and frantic creativity,[62] and was declared the "Best National Metal Record of 2020" by Spanish music magazine Mondo Sonoro.