This hasn't been added to the database yet, initially I thought it was due to a bit of lag behind in regards to latest sets, yet the spoilers for Avacyn Restored have been put in. Is there any particular reason for this?
Also, it may have been addressed before, but I'm not sure where I'd find it, but there are certain promo cards missing from the database, and those that are, usually are missing pictures. This goes for a few of the cards in the Nicol Bolas vs Ajano duel decks.
If these are user submitted, I'd happily scan these in and put them up. I just dont know where. I'd like to have my entire collection on my phone for easy lookup.
Master database for iMtG is still http://magiccards.info, they don't have Koth vs. Venser yet. In addition, this is still semi-manual work and I tend to forget about doing the updates, so thanks for reminding me. I've just updated FNM and Prerelease, next Database Update will add the missing ones.
Scans are coming from Gatherer only, for the time being, and their database is not complete.
Spoilers are done manually, copy-paste.
I can't see which cards from Nicol Bolas vs Ajani are missing.
Rise // Fall and Pain // Suffering. They're up on Dissension and Invasion, but not under the duel decks. I noticed some more are up on the link you gave me and I'll try to contribute any that are missing to there as well.