How Does Disgustingly Resilient Work?

Since at least 5th Edition, Disgustingly Resilient has taken the form of an ability to ignore wounds in the form of a “Feel No Pain” (an actual rule in past times which is still commonly used to refer to similar effects in 8th and 9th, which did away with the name itself), and in 8th Edition this was particularly ...

Does disgustingly resilient work against mortal wounds?

While it does say any attack, so it may reduce the damage by one, but you no longer have the chance to save mortal wounds, they just go straight through with (possibly) minus one damage.

Can mortal wounds be saved 40k?

Note that mortal wounds ignore saves (regular and invulnerable) completely but don't usually ignore Feel No Pain type effects... In the specific example of 8 hits > 4 wounds, the orks would make 4 saving throws (needing 6s).