This chapter was great. With all of these Vindice with pacifiers really make me wonder what the Arcobaleno curse is all about.
Maybe the skeletons were failed attempts to become an Arcobaleno. It's also possible that Checker face had sacrificed a lot of people to perform this curse.
...And why "decrease the Arcobaleno" all of the sudden?
Great chapter! Thought I must say.... waiting a week for the next chapter is torture! Curiously, looks like the mark that the Sky Arcobalenos (Luce, Aria, Uni) carry is engraved on the wall / ceiling.