I just had a thought, Hell's Bells makes us believe that the denarians will be involved.
What with it being the apocalypse, I am trhinking that nearly all the fallen will be active, even those previously in the keeping of the church. THe only place that is secure enough to permanently keep the coins sealed away is the well of demonreach, and that makes me believe at some point it too will be breached, as it is too secure, it has to be breached. The full order of 30 fallen knights would be a force of terrible power, but it would give harry a chance to send most of the order into the well. I wonder what it would mean if all the coins were sealed away, for the knights of the cross. I just noticed something, after shiro died, about 10 of the nickel heads were in the hands of the church , one third of the order, and one sword was put on the side lines. In small favor, when michael went down, another ten or so coins were dehosted, and potentially still out of play.
Stars and stones, well we have hints applenty on the reference. Biggest bet is the star bit is a reference to harry status as a star born. The stone is a bit tricky, there is the stone table, the centre of faerie power. There is the crystal that makes up the outer gates, the crystal eye of the gatekeeper, and the crystal cells of demonreach.
Empty Night, we all assume is the show down between harry and the forces of the outside. There are however references to links between the WCV and empty knight. i had a theory the vampire courts are the result of humans tainted with the touch of beyond the outer gates.
I believe for the trilogy, the sword will have knights, and they will be epic.