I think a big problem with this is that the bonuses you gain from Necrocarnum Shroud are incremented individually. Since they are profane bonuses, each +1 would overlap, leaving you with a net bonus of +1. It's poorly worded, but that's the only way I can see to read the ability. Unless your DM ruled otherwise, that right there would stop the "endless" part of the avalanche, unfortunately.
Destruction Devotion can't reduce your opponent's AC bonus or natural armor bonus to less than 0, so it doesn't lend itself to an infinite chain, but it does let you go for awhile (most creatures have a lot of natural armor, and at least some use armor as well).
Of course, an item of permanent sadism would allow you to do an endless avalanche, assuming you can hit with the first blow and do more than 40 damage per hit.
Crushing Strike requires that you use a full attack action, which precludes the use of Avalanche of Blades.