Lead bassist Iron (yes that is his real name) grew up surrounded by music. His father Marco was always in one band or another performing and touring throughout the Brazilian music scene, so he quickly became accustomed to the music lifestyle of going to loud concerts, watching his father on stage, and it wasn't long before he started picking up the bass guitar writing his own songs, and following in the footsteps of bass legends such as Cliff Burton, Joey DeMaio, and Lemmy Kilmeister.

Guardian of Lightning was formed in 2017 and the band quickly began rehearsing the songs Iron was writing for the band, exploring new possibilities and sounds. After a gig at a local rock club, the band was approached by the great Brazilian rock producer Caio Ribeiro (Sepultura, A-Ha, Ian Paice). Interested in the potential the band had with a lead bassist, Caio had the band into his studio Stage Record to record a two-song demo. The reception was overwhelmingly positive, and the band decided to write more material before heading back to Stage Record with Caio to complete their debut album.

In 2018 the band found out that their producer and close friend Caio Ribeiro was diagnosed with cancer, and the disease progressed quickly. While on his deathbed, he told Iron that the band would go on to create a great album which the world would one day hear. Caio passed away shortly thereafter, and the band took some time to mourn the loss of their dead friend and reflect on what the future held for Guardian of Lightning. Towards the end of 2018, the band were contacted by producer Eurico Tavares. Eurico had assisted Caio with producing the first Guardian of Lightning demo and told the band that he had found the presets for the two previous songs which Caio recorded, which meant that they could be used alongside the new material.

In 2019, the band re-entered Stage Record with their new producer Eurico Tavares to finish their debut full-length album, Cosmos Tree. During the sessions, it was possible to feel the presence of Caio Ribeiro in the studio with them. The positivity and good vibrations were very emotional for the band, and after twelve solid days the result was eight thundering metal tracks unlike anything ever heard by mortal ears before… Cosmos Tree is currently planned for a worldwide release via Eclipse Records in the Summer of 2020.