I think I'm going to write a oneshot about the Bad Batch finding Haste to expand on what I stated in his background.

OC name: Haste

Background:
(This is rather brief because I just wanted to get the idea down)

Haste is a mutated clone with enhanced agility and speed. He is the fifth mutated clone and a member of the Bad Batch.

He only spent a brief amount of time with his batch. As a cadet, he was separated from his brothers to be put through experimental testing to refine his abilities. While the rest of his batch bonded and grew as a team, Haste was trapped in an endless cycle of tests and experiments under the Kaminoans' watch.

Until one day, he snapped.

After the destruction of a lab, Haste was apprehended and placed in a cryogenic hibernation capsule to be reawakened later on. However, he was swiftly forgotten in exchange for more pressing matters and transported to a lesser used lab. That is where he remained until his batchmates (plus Omega) stumbled upon him in the far future.