@KurtinStGeorge & morriswalters
My only issue with this scenario is why Lea would view Justin as the right person to teach Harry? He was never known as a teacher - no other former apprentices are mentioned (aside from Elaine). Additionally there is strong evidence that he was walking on the left-hand path - witnessed by his keeping Bob & likely summoning HWWB to track Harry after his thralling attempt fails. Sure, Lea could’ve been wrong, but I believe Harry says in GS that Lea had always kept an eye over him even when he was younger, so wouldn’t she be keeping a very close eye on what all Justin is upto?
I think it much more likely that Justin & Simon (so Cowl) got some knowledge (perhaps because he & Maggie were ‘friendly’ or through a demon like Chauncey) that there were 2 Starborns in mundane orphanages around the country ripe for the plucking. His goal seems to have been to round them up, train them, emotionally manipulate them & then enthrall them into his personal service.
I’m also a little unsure of why Lea thinks Harry can go back & defeat Justin as a 16 year old.
To go to town on this question you need details we don't have.
My current WAG is that Maggie was messing with the outsiders in some fashion.
But,
Why did Justin need two bodyguards, and why a boy and girl?
We know she was involved in some kind of scheme as related by EB.
It's implied but never stated that she might have been partially enthralled.
Raith may have been trying to use her as a broodmare for a Star Born, and this may have been her scheme as devised by Raith and why Eb said he didn't want any part of it and neither should she.
This last is at least plausible considered in the light of Goodman Grey's comment that Maggie was a piece of work.
In addition when Harry talks to her in the Library, she says something I consider strange.
"I made sure that his father would endure a fitting punishment for what he did to us."
"You and Thomas?"
"And you, Harry.
I know what he did to Thomas, and of course he killed her. But what did he do to Harry?
And considering she was on the run, how did she meet Malcolm?
And in some WOJ, why did Butcher drop the fact that she went to Washington DC while she was pregnant?
And finally in Blood Rites he mentions that when he tries to throw magic at Raith that it feels like Mordite where Raith is standing. Which seems to imply that Raitht's protection is a product of Outsider magic.
Not just empty air and drifting dust, but nothing. A cold and somehow hungry emptiness that filled the space where he should have been. I'd felt something like it before, when I'd been near a mote of one of the deadliest substances that any world of flesh or spirit had ever known.