Which Souls Game has the Best World Design?

These games generally have pretty good world design, but there's also definitely a sizeable gap between the best and the worst, so it's time for my ranking.

Timestamps:
00:00 Intro
01:13 Number 7
03:08 Number 6
04:49 Number 5
07:32 Number 4
10:35 Number 3
14:46 Number 2
18:20 Number 1