Fury's Core is Cinder's stage in Killer Instinct (2013). It is the sixteenth stage that is introduced to the game and the seventh stage (eighth, if counting bonus character Omen and his stage) introduced in Season 2.
The stage takes place in what looks to be a volcano, within an Ultratech-built research facility of some sort. The facility appears to have been damaged by exposure to the intense heat of the volcano. Along the left side of the stage are capsules containing odd-looking organisms, various computers, and research equipment. The right side of the stage is a lake of lava and volcanic rock, which the fighters stand on. In the lava pool, there is a giant, tower-like contraption with rotating cylinders containing coolant. An object that resembles a buoy floats in the lava, and a small, airborne robot will occasionally fly around the background. Streams of lava sometimes run down from above onto the stones in the background.
During an Ultra Combo, movement of machinery in the background becomes frantic, including the giant tower contraption, which readies its cylinders before plunging them into the pool of lava, releasing coolant that hardens the entire pool. The pool shoots a wave of steam over the fighters and solidifies into large chunks of rock.
Cinder's theme "Inferno" is used as background music for Fury's Core. It is a remix of his theme from the original Killer Instinct, "Trailblazer", and features the same melody, except remade using true instrumentals and an overall faster pace, as well as a dynamic element that has been implemented into all characters' themes. LittleVMills, a YouTuber famous for his metal covers of Killer Instinct (2013) tracks, played most of the guitar solos present in "Inferno".
When the characters hold still for a certain amount of time, the music will change to a much more calm electric guitar version of the main theme song for Killer Instinct, "The Instinct". Some of classic Cinder's shouts and battle quotes can be heard in the background, along with the Chris announcer yelling "Blaster Combo!" and "C-C-C-C-Combo Breaker!"
During the track, there is a short guitar riff sounding similar to the last notes of the chorus of Orchid's 2013 theme, "Touch Me and I'll Break Your Face".