Fyodor is generally not shown using a specific, famous nickname for Nikolai in canon; fans mostly point out that Nikolai is the one who gives Fyodor nicknames like “Fedya,” “Dos-kun,” or “Dostoy.”

Quick scoop

If you mean the anime/manga, the safest answer is: there isn’t a clearly established Fyodor-to-Nikolai nickname that’s widely confirmed.

What fans say

  • Nikolai calls Fyodor by affectionate or informal names like “Fedya,” “Dos-kun,” and “Dostoy.”
  • A lot of discussion around the pair focuses on Nikolai’s nicknames, not Fyodor’s.

Short answer

So, if you’re asking “what does Fyodor call Nikolai?” , the most honest reply is: usually just “Nikolai” or “Kolya,” but there’s no strong canon nickname that stands out the way Nikolai’s nicknames for Fyodor do.

If you want, I can also check anime-only , manga-only , or fanon versions separately.