At 3 to rez and armed with s that end the run as well as punish the runner for facechecking (losing a ) Viper is extremely similar to Enigma. The only difference is that it trades strength for porousness and vulnerability to runner . Given that Faust and Parasite are such big threats this is a good trade in the mid-2016 meta.
The most useful function of Viper is as a one-inf card that can help get the corp deck closer to 6 cards in order to activate the Jeeves alliance. Viper also slots well into every other faction too: needs code gates, needs ETR ICE with decent strength and low rez cost and also benefits for the same reasons as Jinteki, with the added bonus of having trace boosting cards in-faction.
- 3+ to break at 0, 2+ at 1, 2 at 2 and free at 3 - however the corp can always pump the ETR trace if they have the s
- 3 cards (or 2 + ) for Faust to break
- 4 for Eater or Gordian Blade to break
- 5 for ZU.13 Key Master to break
- 2 for Cyber-Cypher or Torch to break
- 1 Datasucker counter for Yog.0 to break
P.S. Even though it is porous, it still has a degree of built-in Account Siphon defense, since the corp can pump an unbroken trace to dump s.