The story is an adaption/expansion of Sonic Unleashed, changing some plot elements and adding characters that were absent in Unleashed, like as Team Dark and Knuckles.
This comic provides examples of:
- Alternate Universe Fic: The comic is a reworked version of Sonic Unleashed with more characters added in.
- Blah Blah Blah: In the third panel of page 41, Shadow hears Sonic's speech devolve into nothing as he stops paying attention to him.
- Lions and Tigers and Humans... Oh, My!: The comic adds in Funny Animal extras alongside the humans, making it clear that the various species co-exist together.
- Oh My Gods!: Knuckles says "Chaos have mercy" at one point, with Chaos referencing the original guardian of the Master Emerald.
- The Remake: The Heart of a Monster is a remake of a previous unnamed Sonic Unleashed comic by the artist.