MTL - The Male Supporting Roles Who Are Lonely and Old All the Time - Chapter 137 .The supporting actor who was robbed of his fiancée by the "terminally ill" hero 5

What’s not to love about my new life after transmigrating into a Pet-centered world?
There are mighty creatures that come in all shapes and sizes. They can either be cuddly companions, helpers in your daily life, daring scouts or strong fighters. Or all of the above. Not bad, huh?

I have a family, but the fact is completely overshadowed by my younger sister. She thoroughly hates my guts, and she makes sure that I know this. Every. Single. Day.
Did I mention that she’s disgustingly talented while I am a bottom feeder? A terribly handsome one at that.

I have free rein to run the family business on my own. A small and quaint Pet Store. It should have been great if not for the fact that the previous owner of this body was born with ZERO affinity to handle Astral Pets…

It wouldn’t be a proper transmigration without a gimmick or a system to pave my road to greatness, don’t you think? I have one, but I don’t know if I would be better off without it…

The world is separated into three realms: Aegaryn, Terranis, and Abyssion.Terranis and Abyssion realms have been in disharmony as the Demon King of Abyssion aims to overthrow all the other realms. In the tackling of this and to help the humans of Terranis defend themselves from the demons,A street orphan becomes a sacrifice in a summoning ritual for an S-rank beast. But he is given a golden opportunity of a lifetime as he is transmigrated into a hyena. Guided by a mysterious system that helps him unlock his boundless potential, he evolves with each rank upgrade, a feat no one of his kind has ever known. His journey is one of transformation, both in form and spirit. Each evolution brings new powers and challenges as he is summoned into deadly wars, cruel betrayals, and battles that threaten the very balance of the realms.Along his journey, he meets a summoner whose kindness and ideals are a stark contrast to all the summoners that he had met previously. Unlike the others, she treated him differently. Gave him a name. Through her, he begins to question his path, torn between his primal instincts and the flickering remnants of his humanity.But as the Demon God stirs in the shadows, threatening to collapse the realms into chaos, he must rise to face his ultimate destiny. To protect those who matter, to shatter the chains of servitude, and to ascend to the pinnacle of power—Ash must embrace his boundless evolution and become a force unlike any the realms have ever seen.

I started off as nothing, just a mass of consciousness that slowly evolved. Just your average overpowered existence hungry for a multiverse adventure.