The lovely Sardonyx.
Composed by Aivi Tran and Steven "Surasshu" Velema. First image was drawn by storyboarder Jeff Liu. Steven Universe was created by Rebecca Sugar. Aivi & Surasshu's Soundcloud: https://soundcloud.com/aivisura/steven-universe-sardonyx
From Aivi Tran: "Sardonyx’s theme from Cry for Help. We loved working on this track! A few days before we started recording, I began revisiting classical pieces with big chromatic chords in an attempt to get my piano chops up and ready!"