Fics like The Legacy of Sun

The promise given by Kamados' ancestor to their lifesaver carries a weight they don't comprehend when five hundred years later the Gods decide to collect what was promised to them and Tsugikuni Yoriichi, the legacy that would receive the same blessing and complete the divine decree of destroying Kibutsuji Muzan. Meanwhile, a child was born to bloom the true blue flower that should never exist. When the child of blue was born, he is destined to bury his family. Stagnant water is poisonous, so Giyū couldn't stop moving forward and unwavering. There's a price that has to be paid for bringing abomination to this world. Their path crossed under the tutelage of Sakonji Urokodaki An Alternate Universe where Tanjirō was born in the same generation as Giyū

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1. all this blue by Yoursplural (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
2. The Tide of Fate by CapoBeGone (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
3. Five things learned about Tomioka Giyuu, and one thing forgotten by Vexfulfolly (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
4. Small Fire of Winter Stars by phabulousphantom (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
5. The Hashira React by CurlyandNerdy (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
6. To Who You Were, Before by SoggyAquaLoaf (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
7. Mother Giyuu by MangetesmortsPrincesse0 (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
8. Hinokami's Future by fallingakiangels (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
9. Demon Slayer Characters react to the future by Lem0nShr00m (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
10. Inevitable by HaiYunLan (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime))
11. Blood Runs Thicker Than Water by silviarose (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
12. To live in the Aftermath by AP986 (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
13. Baby Hashira by hamhugs (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
14. but no more worries, rest your head and go to sleep, maybe one day we'll wake up and this will all just be a dream by abstract_psychopomp (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
15. What Do You Mean he's a Baby?! by Night_Of_Fire (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
16. A Flower That Blooms In The Rain by EmbretheWorld (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
17. Kataware Doki by wxxxxxxxxr (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime))
18. clear blue skies by orphan_account (僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia, 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), more)
19. Snake in Water by imkazzzz (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))
20. When Floodgates Burst by orphan_account (鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime), 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Manga))