If you want to face the secret boss in your first playthrough I found a helpful guide on how to set it up (pc only)

[Clue]

https://www.reddit.com/r/MetaphorReFantazio/comments/1g9dhr1/unlocking_the_hardest_difficulty_regicideking_of/

[Unforgiven]

that king of kings difficulty is literally regicide without dmg reduction and you get more loot, lmao

[Clue]

Originally posted by Unforgiven:

that king of kings difficulty is literally regicide without dmg reduction and you get more loot, lmao

sorry is the king of kings difficulty not the same as regicide or are they distinct?
=

[dustin1280]

Tag, probably going to enable the super boss on my first playthrough.
I am grinding before the final final dungeon anyway...

[namarataka]

There is guide on steam but I can't find it :/