Flames Of Oblivion

Caught in a terrifying fire and being forcibly transmigrated to another world with no knowledge, forced into a low level skill, exiled to being a background character, a mere "extra". Zephyr was forced into the protagonists school, has no dreams of being important, suddenly a major crisis occurred, the protagonist nearly dies. Given up on life, Zephyr saves the protagonist and gains an achievement.

[Congratulations on becoming a side character!]

How will Zephyr use this to his advantage to live a normal life.?

(Schedule; whenever i have free time (usually Fridays))
Cover; Made in Waifu Diffusion
Warning; My first book! Please take this lightly, and do send some advice.