Lazarus is an AI robot entity made up of liquid. (See the image for some info)

They were part of a series of liquid robots created from an advanced planet before it was soon destroyed. As far as they know, they're the only one left. They currently travel around the interstellar empire with no real direction.

Lazarus's liquid form design is mostly inspired by KoroSensei from Assassination Classroom (my they've got some familiar looking faces don't they), and Deoxys from Pokémon. Also has some inspiration from the Gem race of Steven Universe.

The Mech Body Mk. II has inspiration from a variety of sources, mostly this little robot guys in some lesser known MMO called "Pixel Worlds"

But also has some inspiration from Hex from FNF as a big inspiration as well. Some random references include FNF-inspired arrows on their arms, and a super oddly specific detail on their hat in which the "U" vaguely resembles Johnny Joestar (JoJo's Bizarre Adventure Part 7)'s hat horseshoe.

Yeah the jacket is sans ecksdee