Shard the Metal/Mecha Sonic is the original Metal/Mecha sonic, but after a confrontation around Mount Mobius (the place where Sonic Spinball takes place), allows Sonic and Tails to get away as he tries to push back lava (almost in a similar vein to the CD OVA) but later on in the series he gets rebuilt and repaired by a disgruntled Chuck before his Auto repair kicks in preventing any upgrades or the sort, as he becomes more alike sonic in personality and Morality than only appearance thanks to his Power Core and becomes part of the secret Freedom fighters, but due to being part of the secret sect of the fighters, he can’t celebrate or any of the likes and yearns for People to be loved or to be like a family but due to his past and having to be a secret, he only has the other secret freedom fighters and Nicole.

And unlike Nicole, he was always a bad guy in the past up until his sacrifice, and none of the others outside see anything of what he does as good due to having to be a secret, and after a encounter with a new and improved Metal Sonic who commits self destruct which damages Shard’s Core with other heavy damage making his auto repair too slow, and with his last moment he could only warn Nicole about Metal Sonic’s upgrades, but he also tries to confess his affection towards Nicole but he falls unconcious before he could.

and was never seen since and obviously with the Sega and Archie Split and reboot of the comics, We never got to see Shard again.