Up to 75.1% of souls got and level 54. Completion rating 93.4%.

For my reference, souls I haven’t yet got -

16 – Slime
19 – Manticore
23 – Yorick
24 – Skeleton Farmer
29 – ???
30 – Tombstone
32 – ???
34 – Quetzalcoatl
62 – Heart Eater
71 – ???
73 – Decarabia
74 – Dead Mate

(Pause. Why doesn’t the Dead Mate have a Soul Rarity rating? And why do you not seem to get XP for killing one? Resume.)

75 – Bugbear
79 – Alura Une
80 – Great Axe Armor
81 – ???
82 – Mushussu
88 – Black Panther
89 – Mud Demon
90 – Giant Slug
91 – Werewolf
92 – Flame Demon
94 – Arc Demon
96 – Slogra
97 – Stolas
98 – Final Guard
99 – Malacoda
100 – Alastor
116 – ???

There are, so I’ve heard, two souls that can be used to get past the spikes. I’ve got some way to go to be sure that I’ve got it…