This probably will see the most play in Jinteki as a fairly reliable way of getting high-value subroutines to fire. In Jinteki, the most dangerous target is Bathyonymous' 3 net damage. Secondarily you may see an end the run or maybe some wacky play around Aimor or Otoroshi. This card gets nuts on HB ice. Bloop and Fairchild 3.0 can inflict a brain damage, Tyr can inflict two brain damage or "trash a Runner card and gain $3".
I suspect this will see play in HB brain damage decks because paying $2 to reliably trigger a subroutine of an unrezzed ice is crazy value, and the card that creates this crazy value protects itself under its own forcefield of pain.
The most practical counterplay is probably Pinhole Threading or Caldera. If you can deal with uninteractive damage with Caldera, then Nani is just an (exhaustible) engine of end-the-run subroutines. Oh by the way Tyr also has a subroutine that can trash Caldera. Light the Fire theoretically could work, but probably will not. (Incurring a brain damage is a big cost against a deck trying to inflict brain damage, and at least one identity likely to use Nanisivik - Aginfusion - can bounce you out harmlessly on a LTF run).
I'm not sure a self-protecting card which can trigger a subroutine on an unrezzed ice is workable in the current card pool.
Update: Nanisivik is banned in Standard as of March 2023. "Banning Nanisivik Grid was a hard decision—it is very frequently an interesting card, but installing one on Archives makes it extremely difficult to trash without the use of specific tech cards." Banning Nanisivik makes it easier to delay runs on Archives. Having to run Archives to deactivate Jinteki cards like Nanisivik was not very fun. I think Regenesis is closer to a right track, the corp has to ante up an agenda in Archives to use Regenesis, so breaking up a Regenesis play is more rewarding.
If you can spend $2 and a click to trash a program and push the runner to spend $3 on trashing the grid, that could be very promising. Anecdotally I am seeing fewer runners using the self-recurring conspiracy breakers on Jinteki.net, particularly MKUltra.
— superheronationAlso, cards like the Sy. Excavator help give you a little more value getting ice facedown in archives than just discarding.
— superheronation
In Weyland, this could lead to an unconditional trashing of one program or even trashing one installed card. At 2 influences, it is a great upgrade for rig shooting.,
— Diogene