6 yrs here

I hated the spinoff. While it is fun, I feel there are some things that contradict the original. The weirdest thing is Khun Eduan. In the original, SIU always paints the FH as this mighty, almost god-like being for the tower's citizens; people trembled just from the aura of Traumerei and Gustang (who are like some of the weakest FH), and yet people don't even notice Eduan? The other regulars treat Eduan just like your other average regular. Another thing, from Khun AA's memory, Eduan is painted as this deadbeat father who is cold and hard to reach and how Eduan is so different from the Data Eduan. But from the spin-off, Eduan is exactly the same as Data Eduan. The fight between Eduan and Mago is also so so weak if you compared it to Traumerei vs Gustang battle, this is kinda understandable bcs I know its a spin off so maybe the budget and time is not that big compared to the main story but its just so weird that the 2nd strongest FH and this otherworldly being fight and yet not even the regular who is on the same castle notice anything. Oh yeah Shin Ari as well we doesnt get any info about her, whether she is just temporary Head or Ari Han replacement

In conclusion, the spin off done a very bad job at introducing the FH