Did Shadow Milk notice him when he was almost released?
I think the best way to answer this is to start by explaining where specifically in the plot my au becomes canon divergent, that being scene #7 of episode 2, where Elder Faerie and ShaMilk have their fight
Unlike in canon, breaking free from the Silver Tree left ShaMilk more drained than he anticipated, so rather than Elder Faerie fighting him off at the cost of his only life, he just barely managed to make ShaMilk retreat and survive (did I decide this just because I wanted Elder Faerie to live? Only partially lol)
At the time of ShaMilks release and encounter with the Brave Gang, Custard the iii is still in the airship wreckage somewhere in the forest, so he doesn’t know about ShaMilk or how he’s the bad guy (this helps define their dynamic later in the au)
When ShaMilk retreats into the forest he finds Custard the iii then and puts 2 and 2 together from both the boys appearance and the airship wreckage that he must be acquainted with PV and the Brave Gang one way or another.
And since Custard knows the Brave Gang but DOESN’T know about ShaMilk being bad, he figures the boy is the perfect pawn to use against them.
He immediately begins his scheme the moment Custard is awake again.
Obviously SMilk is going to play as one of his personas, maybe not changing his appearance but using a concerned and warm personality to make Custard feel more secure
“Now what is a young cookie like you doing in *such* a dangerous place hm? Why you’re *so lucky* I happened to find you!!”
And for this particular scheme I decided he wouldn’t be doing any disguises with it.
After introductions he makes a comment about Custard’s tiny crown and staff and this ofc gets Custard talking about how kingly he will be
And sticking with the concept of Shadow Milk not changing his appearance and only his personality
He’ll act like he’s doing Custard a service
Something along the lines of
“Well I should accompany his young highness through these treacherous lands then!!! Maybe offer some entertainment, after all a king does need a jester!”
Custard would easily agree to anything that makes him more ‘kingly’
So Shadow Milks plan is already going perfectly
Easily making Custard think he’s in charge and that SMilk is just doing right by a future Royal
Thats the start of their acquaintanceship, rather than Custard the iii
being present for ShaMilks release.