Upon first read it's easy to get excited and imagine this card says:
,: The Runner loses 5 or an Imp Counter
But in reality it's not so simple to make this card work. The runner must have 5 or a virus counter on Imp when they access Mumbad Virtual Tour. If the runner is too poor or doesn't have a loaded Imp then this is effectively a blank card. What's more, it is quite unlikely the corp will be able to land its effect once the runner knows what it is.
Now it's clear that Cyberdex Virus Suite is superior if the goal is to eliminate virus counters, so that only leaves draining credits from the runner. That's not easy to land either well. Since Virtual Tour only activates when it is installed there's the question of where to put it.
- HQ: Doesn't stop Account Siphon, likely to be the last card accessed as well.
- R&D: Doesn't stop multi-access and is likely to the last card accessed as well. Does not even activate in the case of Indexing or Keyhole.
- Archives: Again it's likely to be the last card accessed, but unless there's a NAPD Contract, Fetal AI or The Future Perfect then the runner won't be spending any credits during their access phase. However there are a number of reasons why this won't get triggered off a successful Archives run too (Sneakdoor Beta, Retrieval Run, Hades Shard, Security Testing or Patron being the most common ones).
- Naked Remote: The likelihood of getting checked is quite high, unless the corp is playing a ambush shell game. It will only be effective if the runner has 5 at the time of access, or likely the runner will budget so they never fall victim to its effect.
- Protected Remote: It's likely that the runner has spent a few s just to get into the server. If it doesn't fire the first time the runner will try to have 4 or less left over the next time they access.
How to make Mumbad Virtual Tour work:
- Hostile Infrastructure is a nice combo to magnify the hurt
- Self-destruct along with a Melange Mining Corp. - if the runner has 6 let them in. If the runner has less than 6 then the corp can win the trace for 3 net damage. This combo actually works better AFTER the runner knows there is a Virtual Tour in the remote.
- An Offer You Can't Refuse
- Susanoo-no-Mikoto (Virtual Tour in uniced Archives only)
- NAPD Contract it doesn't work if the runner has exactly 4 but it does make things more challenging - keep in mind that Jeeves Model Bioroids or Efficiency Committee+Shipment from SanSan both enable NAPD as a never-advance play. Also Tennin and PAD Factory allow the corp to 'advance' any card.
- Spark Agency benefits from a nice way to bring the runner's credit pool back down to earth if they ever get out of control
- Fake Crisium Grid in a horizontal deck - often the runner tries to get rid of those first if they are playing Keyhole or Siphon. That will guarantee the runner has 5 on hand when they access.
Note: It can be used in Gagarin too - just put it on a central server.
Overall Rating: Not enough raw power to justify the deckslots without a good strategy.
The timing depends entirely on the runner and there are ways to play around it by accessing last and/or having 4 or less on hand. CVS is better against Imp and additional econ cards are better in general. The best possible result might be draining multiple Ghost Runners but that's unlikely to happen often.