using a powerful creature's name as a title has extra consequences when the creature is real and can take offense, especially if fey of the setting specifically get touchy about names. Gets into some Niobe/Arachne styled hubris tales. Funny to imagine the real Baba Yaga coming after John Wick for bearing the nickname proudly, or teaming up with him to hunt down the ones who gave him the nickname.

When I was in middle school I ran my first long term game in a free-style ttrpg we called "The Journal Game" and early on I had an Assassin based off of Gyro Zeppeli from JoJo's Bizarre Adventure 7th Part, Steel Ball Run, show up. Problem was I never actually read the manga, I just knew his power set. I ended up stealing his powers (the ability to cause anything to spin) and mixed it with the name of another character from the series (Stephan Steelball, but I changed it to Steven Steelball because it sounded cooler (I guess??)). My setting back then was basically JoJo's Bizzare adventure mixed with Devil Man and Kid Icarus Uprising and just other cool things I liked lego bricked together in a whimsically rules light system. Those were some awesome times playing.

My players toke a job from the local criminal underground organisation (they are on a mission in the session I am running in like 45 minutes) and the organisation mostly refers to everyone in it by nicknames. The leader is named "Fang", one of her bodyguards goes by "femme fatal" etc. This is also partly beause one of them is an eladrin and he is the one responsible for communication via sending or the "eary token" mechanics from the hexblood lineage and I wanted to give them some fey flavor. Also it was great to terrify my players when they met them for the first time and the organisation knew their names and some background stuff becaus of course they did research before hiring someone (Also the party was very open in this city about their names and the stuff they are doing)

Apologies that this comment isn't about the video topic but I saw your appearance on Roll For Combat last night and you mentioned medievalism and having only experienced 5e before, so I thought I'd recommend something you should read: Pendragon. It's a whole RPG about campaigns set in Arthurian legends. They also recommended Ars Magica which I also love for its medieval setting!

One can never watch too much John Wick. The difference between 5e and 1e is scope. In 5e, you are basically on vacation in the game. In 1e, you lived there. As your PC scaled up, you built the mythology. So, start the criminal organization. Hire John Wick or Dread Pirate Roberts or Deadpool. Decide how that can happen. Then you have a living world that your party can vacation in. Everything works, if you let it.

In Polish her name means Old Broad Jaga. Babcia = grandmother; babka = chick/gal, baba = old broad, more or less. No one would call their grandmother "baba," it's not a curse word but it is somewhat rude and dismissive, but the words have the same origin. Women and girls call each other "babki" as an endearing term, it can be slang for "woman," it can also be dismissive/meaning "some rando woman" in some contexts ("me and my girls" vs "I was bothered by some girl"). "Babka" also means "bunt cake." "Babcia" always means "grandma."

Not sure if you've read much of Forgotten Realms, but check out a wiki on Artemis Entreri if you haven't read about him.