The owls will tell you a unique password that looks like it is made of upper case vowels but which is actually made of Greek, Coptic, and Cyrillic Unicode!
The vowels correspond to sets of Unicode homoglyphs: letters that look the same. None of them are from the actual ASCII set, but they should look idential to their ASCII equivalent.
If you are using the right sort of typeface, an adversary who is spying over your shoulder and sees a password starting with "E" wouldn't be able to tell if it is an E (latin capital letter E, which would never actually be chosen by vowel-sanctuary), Ε (greek capital letter epsilon), Е (cyrillic capital letter IE), or Е (lisu letter E). Each vowel that is used comes from a set of two or three choices spread over different Unicode code pages.
The regular entropy of the password is printed (⚄), as well as the entropy of the password if someone is spying over your shoulder (☭): the adversary knows which sets of homoglyphs had been used in each position, but doesn't know the actual glyphs used.
