Audrey analyzed many things at once as her mind whirled.
Mr. Hanged Man said that Qilangos was a lone wolf who doesn't trust anyone. Only he would know of his own plan. Other than my early discovery of him, there shouldn't have been anyone else who knew he would attempt the assassination tonight…
I only told Father and Mr. Fool that I suspected that Qilangos was disguised as Baron Gramir…
Although there's a telegram cable in Duke Negan's mansion and he would've been able to send out information in time to ask for help, there's no reason to hide that… Dad's puzzlement implies that the powerful being that killed Qilangos wasn't within their expectations…
Combining all of the above, I can almost be certain that the person who killed Qilangos was Mr. Fool's Blessed!
Plus, only the unique model of the Tarot Club can create such a strange situation with unclear motives!