Hi all. I have just bought the Mega Box and subscribed to the Vault in order to get the STLs for the Nightstalker prints available. This means that I have the following models available to either build or print in order to make a competitive list (as a noob having a half decent list must surely help…)
Anyway, this is what I have built from the box or can print multiples of from the Vault:
Horror
2 Regiments of Scarecrows or 1 horde
2 Regiments of Tormentors or 4 Troops (mix of each)
2 Hordes of Butchers or 4 Regiments (mix of each)
2 Butcher Fleshrippers
Terror
x Bloodworms (3d print proxy models) - unlimited
x Soulflayers (3d print) - unlimited
x Shadow Hulk (3d print) - unlimited
1 Portal of Despair (proxy)
1 Esenyshra (proxy)
1 The Dream Hunter (3d print)
x Dread-fiend / Fiends (3d print)- unlimited
xMind-Screech (3d print) - unlimited
I dont want to purchase anything else so any tips on what to do or if you are feeling generous with your time… build me a list 
to get me started. Looking to play at 2300pts