The ending of the Eminence in Shadow anime doesn't have a one-to-one correspondence in the manga. Sometimes, anime adaptations condense or expand storylines, making it tricky to determine the exact manga point where it ends.
It's a bit hard to pinpoint exactly. The anime's ending might not align precisely with a specific chapter in the manga, as adaptations often make adjustments.
The anime's ending in the light novel is somewhat ambiguous. Sometimes, anime adaptations don't align exactly with the light novel's progress. You could explore online forums or the author's statements for more clarity.
I think the best place to start is from the point where the anime concluded. However, for a thorough understanding, beginning from the start of the manga allows you to catch all the nuances and subtleties that might not have made it to the screen.
The Eminence in Shadow light novel is finished. It provided a conclusive ending for the characters and their adventures, leaving fans with a complete narrative.