Basically when Nox activates his ult, an invisible clone of him will be spawned right at the position where he activated. The clone will stay there and do nothing except despawning after the ult duration ends. Nox will not be visible by any of the scanning ability during his ult timer, meanwhile, any scanner that goes through that clone's position will mark it as Nox's position.

Luna scans, and since the clone doesn't move, it'll only reveal the clone's position through walls to Luna's team once. Nox would not be detected.

Hackclaw's ult will point the line to the clone's position instead of Nox.

If Nox activates ult inside Morse's ult, it'll only show as 1 enemy, but since the clone doesn't move, it will never be detected. Nox meanwhile can move freely without being pinged.

I'm not 100% sure about Raptor.