I figured out a bit more of "Butcher's Tale." I can't figure out how to play the whole thing at once, so I just overdubbed the three-note bass part. It feels like the whole legitimacy of the song is ruined when it comes to a part without that three-note figure though. Because I don't know the parts that go there instead.
Musically, the song is made by the staccato chords' and the bass part's complementing each other.