Aha! I knew it was implied somewhere that Yamato belonged to Sparda, but I couldn't find where - it's in the description in the Equip menu as Vergil, which I just opened by accident in Bloody Palace mode XD;

And I have asked neighbor to turn down her bass, which she did, but I think I'm doomed - whatever the walls are around here, any bass it too much bass, 'cause it goes right through.