I don't know if it has been said before, but it takes 64 "murmurs" to unlock the second requiem. I didn't count the first one, but I'll probably count the third one.
It seems to me like farming the relics to farm the requiem mods, then farming the thralls to farm the right order of requiems, to farm the weapon/ephemera (possibly also armor/color pallet?) is the longest jog in the world. Like, how do you do to dispose of yours quickly, if you don't like/have the weapon already, and don't want to go through 10 hours of farming thralls and requiem relics to yeet him out into space?