Swedish melodic death metal supergroup the Halo Effect includes some of the most storied and esteemed players of Gothenberg's metal scene, with members of long-running bands like In Flames, Dark Tranquility, Passenger, and more all contributing to their atmospheric and technically exacting sound. The group formed during the early days of the COVID-19 pandemic and sought to bring back the classic death metal sound of Gothenberg's early-'90s bands with records like their 2022 debut, Days of the Lost, and its 2025 follow-up March of the Unheard.