Here is the full list of all 30 Shad'O achievements.
Gulp a dozen "Shell" shadows down with your Greedy companions.
Defeat the last Boss.
Defeat the third Boss without using the "Sacrifice" spell.
Fully explore the William’s memories map.
Win the "Ice trap" battle without using the Greedy companion.
Cast 20 spells during a battle and win it.
Win the "Dark woods" battle without using any range boost locations.
Reach 2500 light resource in any battle.
Kill 5000 enemies.
Get 250 magic resource in any battle.
Cast at least once each 10 spells during a battle and win it.
Win the "Underneath the Christmas tree" battle using only Collector and Pulsor companions. (Spells are allowed)
Win "The slabs waterfall" battle using only Collector and Rainbow companions. (Spells are allowed)
Reach 1000 light resource in any battle.
Pass all the special battles.
Use 10 different companions during a battle and win it.
Destroy 10 "Bomb" shadows before they explode.
Watch the credits till the end.
Win "The endless corridor" battle using only Collector and Greedy companions. (Spells are allowed)
Defeat the second Boss.
Defeat the second Boss without using the Doc companion or the "Care" spell.
Unlock all the spells in the book.
Kill 2500 enemies.
Defeat the first Boss.
Defeat the first Boss without letting any of your companions get electrocuted.
Kill 1000 enemies.
Unlock all of your companions’ upgrades in the book.
Sell 30 companions during a battle and win it.
Save all the memories in nightmare mode.
Make it so that 4 Collector companions get destroyed in "The snowmen’s waltz" battle.