u/Direct_Beach_6032

It's a Chinese fic from Moriarty the Patriot / Yuukoku no Moriarty.（憂国のモリアーティ/忧国的莫里亚帝）

The title was

【忧莫｜福莫】War memoirs by Sherlock Holmes - Chapter 1 - Antoni...

（The author’s name was only partially visible in the preview, so I only know it started with “Antoni...”.）

Original AO3 links:

One part of the fic I remember is:

还没等我想出一个合理的措辞，威廉摘下礼帽优雅地向我道别。此刻我终于意识到，为何他身上会有如此熟悉的感觉。初次见面后，我似乎透过镜子，看到了世界上另一个夏洛克·福尔摩斯（We‘re two of a kind）。

Thank you so much!!