The Architect(Nix)

The Architect is the supreme being in the Keys to the Kingdom series.

She is comparable to God. Furthermore, she was the first being created out of Nothing. ( the second was the The Old One.) Her power apparently is superior to all others including the Old One, the only other fully formed being to appear from Nothing.

After creating the Kingdom and the Secondary Realms, she designated the Morrow Days as the trustees of her Kingdom, one of which was her son, Lord Sunday. In addition, she also created a will that was to be executed by the Morrow Days before disappearing without a trace.

Her will is broken by the Morrow Days into seven pieces, separated, and hidden. Each of the trustees are afflicted thereafter with one of the seven deadly sins. They cannot be cured unless the Rightful Heir designated in the Architect's will is found and granted power of the keys to their domains.

It is unknown if the Architect still exists or is dead. The raised rats are very interested in this question and used it as a question in their mercentile Q&A in Drowned Wednesday. It is possible that those rats were working for the Piper as we learn that he is alive and plotting in Sir Thursday.