He did not say he was a vanilla mortal.

"Just plain folk?"

"Yeah"

"Not supernatural?"

"I wish, Vanilla mortal."

"You're a liar."

"Excuse me?"

"I said you're a liar. I saw you during the fight at Wrigley, Kincaid. You fired a dozen shots, on the move and dodging bad guys the whole time."

"What's so supernatural about that?"

"In a fight, just plain folks miss sometimes. Maybe most times. You didn't miss once."

"What's the point of shooting if you're just going to miss? I'm as human as you are, Dresden. I'll see you later." 

With cassius, it was the mortal body that Nic thought was weak, not the fallen inside the coin.

he could have Ursiel and the other (I don't remember the name of Cassius' fallen right now) with him next time.

Or was Lasciel rejecting Harry now as a host, going instead for revenge because she was so soundly rejected.

I find it troubling that a shadow of the Fallen could turn up on Holy ground to begin with, I thought that was impossible. 

I don't think Lasciel can do that and still be able to whisper to Harry

Don't you get the feeling that at some point Harry is going to have a conversation with Lasciel,

everyone assumes that lash is gone. 

Lash's "conversion" was a staged event specifically targeted to soften him up.

So, from what I've seen, what you accept as cannon is at best a fishy sounding rumor to me.  And does not absolutely state that that the entity is Lashiel in any case.

Does anyone else see EB as the bad guy, he is the blackstaff after all he didn't get involved with helping Harry out tell he found out about the bloodline curse affecting him. I mean come on he's totally black council, he's just using the "gray council" to occupy harry and to weed out the good guys from the ones he can use.