Nightcreeper lists as one of its benefits “30 percent Shadow Step cast speed.” But a simple test of recording and going frame by frame revealed that it didn’t change the time that Shadow Step takes at all. Also checked during a match and it didn’t make Reaper invulnerable any sooner than normal.
Silent as the Grave: Doesn’t appear to function at all, or if it does then the reduced volume is negligible. Reaper’s footsteps are still extremely loud and he still loudly yells “Flanking!” and whatnot whenever using Shadow Step. Tested by watching replays from the enemy’s perspective.
Phantasmic Flux: The amount of overhealth Reaper gets from from damage dealt is often dramatically less than he should get. The amount of overhealth he gets from dealing a certain amount of damage is incredibly random. No clue what’s going on here, when I test by killing a character in the training ground with Cass with the same item it always gives him the same amount of overhealth (within 1 point due to some rounding behind the scenes I assume) every kill but Reaper will usually get less than half the overhealth he should. That’s even after having already factored out the second point I’m about to bring up. Secondly, it’s very clear that Reaper’s innate lifesteal % isn’t counted towards generating overhealth, whereas all the other Stadium items that increase lifesteal increase the amount gained as expected.