Would Asabi notice the switch?
Only if he's still in the picture. We didn't really see much of Asabi after St. John entered the picture. Maybe he's already started his occult shop.
There is a Xander is costumed as Lex when the Halloween spell hits and ends up in the DC universe in Lex's head. Presumably Lex is in Xander's body. Only three chapters mixed in with a bunch of other story idea chapters. The writer is annoying that way, lots of good ideas and almost no finished stories.
From the third chapter after Xander has given Lex's body Plasticman's powers.
"Lex," Mercy said seriously, "I have some concerns."
Xander reformed the top half of his body, leaving the bottom half a large pink puddle. "I'm listening," Xander said seriously, sensing her disquiet.
"Your behavior has radically changed over the past few days," Mercy explained. "Not enough to activate the Doppelganger protocols, but more than enough to suspect you may be having your mind influenced in some way."
Xander completely reformed his body or rather Lex's body, making him look like he was in his early 20's and spent his spare time participating in bodybuilding contests. "Perfectly understandable, would an explanation of my current mindset help set your fears to rest?"
"Yeah, but that's also an example of a complete departure from your normal behavior," she pointed out.
I agree that does sound like a strange compilation of plots tied together.
