La “Black” Luna

Magic Flute that Calls Panic. The Noble Phantasm of Rider of “Black,” Astolfo. Among his abundant Noble Phantasms, it is the only average one that isn't very cheat-like. It's an Anti-Army Noble Phantasm, but its power isn't that great, and while it's effective against small-fry enemies such as Dragon Tooth Warriors, it's a bit unreliable against other Servants.
However, just as the name magic flute implies, the true fearsomeness of this Noble Phantasm is the chaos and confusion caused by the shock of its overblown sound. If someone skilled with the flute blows this flute (though it's much bigger than a normal one), it's capable of even taking away all hearing from the target. Their ability to fight won't necessarily be stopped just by cutting off one of their five senses or by being sent into disorder, but even so, lacking the ability to hear would disadvantage a Servant, at least a little.
It wouldn't be much of a handicap for highly experienced Servants, but during clashes between first-rate Servants, there are times where the slight opening it creates can decide the battle.
In that sense, it truly is an auxiliary Noble Phantasm.

Fate/Apocrypha material: Fate/Apocrypha Encylopedia