He is identically looking to Akame. The only difference could be that he is younger, because there are no signs of chin hair, what normally all veterans have.
This white dog who appears with Tokimune (Gin's substitute) and Tony (John's substitute) is Akame's substitute whenever he is away. Akame's substitute, along with Tony, got killed when humans arrived in Ōu. He got shot to death by the hunters on a nearby cliff.