The process through which I have went through to come to my choice as to who The Warlock is is a very lengthy and tricky one.
Before The Warlock is published, I have been looking for clues as to who The Warlock might be. [aren't we all? ]
I tried looking at the titular characters of the previous books to generate an idea of who the Warlock might be.
There's Nicholas, Dee, Perenelle, and Josh. They are main characters of the series. If this is the case, shouldn't The Warlock (and The Enchantress as well, of course) be named after a main character also? I thought of Machiavelli (and Sophie for the Enchantress). After all, Machiavelli is one of my favorites.
Later on, I got another clue from Awakenings Episode 13 (53:50).
Someone asked Michael, "have we met the humani, immortal, and Elder who are Warlocks by the end of book three?" Michael's answer was no. Then, one of the podcast's hosts asked a follow-up question, "have we met the Warlock by the end of book four?" Michael answered yes. Then he revised his answer to "candidates."
Since I am very particular about a branch of Philosophy called Logic, for a very long time, the way I understand this conversation is this: if we haven't met the Warlock (or candidates) by the end of book three, but we would have met the Warlock (or candidates) by the end of book four, then the Warlock (or candidates) is a new character we've met on book four.
This logic made it clear that the Warlock can't be Machiavelli.
However, I really want Machiavelli to be the titular character of book five. So I tried, again and again, to find a loophole in the logic:
maybe Michael changed his mind,
or maybe he's still thinking who will be the Warlock,
or maybe I just misinterpreted the conversation,
or maybe there's something more to it that I didn't spot.
Not until recently did I find a possible explanation: Upon reading The Warlock, I learned that we have met some candidates by the end of book three (Mach & Billy) but we only met all the candidates by the end of book four (Aten). Maybe Mr. Scott is answering the question of when we would have met ALL the candidates rather than when we would have met some of the candidates for the Warlock.
We would have met some candidates by the end of book three, but not until by the end of book four would we meet all the candidates.
This implies that the Warlock could come from any of the first four books.
There was a time that Mr. Scott said that The Warlock might not be an immortal humani. This is probably because of Aten, who is called a waerloga in The Warlock. But then, he said "might." It's still possible that it's Machiavelli.
Now, I can no longer worry about guessing that The Warlock is Machiavelli.