The cave is a dark cove with the remains of an alter, stairs and other temple-like structures. Large spiders and webs with trapped beings inside them litter the cave, and more members of Sadira's guild can be seen in the background.
During an Ultra Combo, the cave begins to collapse and a giant spider emerges from within the deeper sections.
Sadira's theme "Ballet of Death" is composed by Mick Gordon. It has a creepy metal rock music vibe, along with creepy sounds between the screaming and buzzing. It features vocals by Elspeth Eastman.
If the fighters hold still for a certain time, the music will change to a remixed version of the original Killer Instinct theme, "The Instinct".
Sadira's render in Assassin's Cave
Concept art of Assassin's Cave
Assassin's Cave in Killer Instinct Season 1 and 2.