This is my take on Mono Shadow in Expedition. I took the deck from diamond 3 onwards and finished a few hours later with an 27:7 record. Most of the cards in this list are pretty standard (Icaria, Devouring Shadow, Eremot etc.), but I found some spicy inclusions that worked well too.
Damara, Deft Saboteur can act as a pseudo removal against smaller units, 3 free damage to finish opponent or Sites of and/or as a simple value option that can also carry weapons.
Auric Interrogator works really well with
Makkar's Quiver and all of the weapons in the deck and can draw once with
Spiteful Strike out of the market.
Beastcaller's Amulet and
Dueling Pistols work well with
Varret, Hero-in-Training, all your flyers (but be aware that weapons on Eremot vanish after his transformation) and Interrogator. The rest of the deck is pretty self-explanatory and the playstile is really straightforward, just try to get a hand with access to 3 or 4 power and some units and maybe some removal and play your basic midrange playstile from there (try to evaluate early if you need to be aggressive or defensive, dependend on the opponents deck and your hand).
Good luck and have fun!
Also I have a quiver, do you think running 4 is necessary? Does it benefit to have multiple in hand?
4 Blightmoth (Set1085 #14)
3 Makkar's Quiver (Set8 #123)
4 Two-Face (Set8 #126)
4 Vara's Favor (Set0 #35)
4 Banish (Set2 #207)
2 Devouring Shadow (Set0 #36)
3 Marionette Cross (Set4 #218)
4 Eremot, Mindsplinter (Set8 #327)
4 Impending Doom (Set1 #286)
4 Icaria, First Reaper (Set1087 #11)
3 Karvet, Solar Dragon (Set7 #146)
4 Nahid's Distillation (Set8 #55)
2 Pale Rider's Timepiece (Set8 #144)
2 Vara, Fate-Touched (Set1 #307)
4 Seat of Mystery (Set0 #61)
16 Shadow Sigil (Set1 #249)
1 Time Sigil (Set1 #63)
4 Xenan Insignia (Set7 #184)
--------------MARKET---------------
1 Avoid Death (Set1085 #13)
1 Destruction Chant (Set8 #182)
1 Edict of Makkar (Set7 #123)
1 Ghar, Master Sandmage (Set6 #49)
1 Spiteful Strike (Set6 #186)
That being said, my deck is still fairly different. I don't use weapons, as I am too afraid of the card disadvantage. (BTW, Unseen Longbow is probably the best weapon for mono-shadow). Once I pulled the weapons, I substituted Dreamsnatcher for Varret, and I put in Dizo, Cabal Racketeer, which is just amazing. (For some reason, Mill is very popular on the ladder right now, and I love grabbing Mournful Deathcaps with it). I also put back Incarnus instead of Pending Doom, and I've won plenty of games with the card I got from Invoke.
Again, thanks for some good ideas!