Here is the full list of all 19 Chaotic: Shadow Warriors achievements worth 1,000 gamerscore.
Search for Maxxor in Gigantempopolis
Find a way out of the Prison Cell in Mount Pillar
Defeat the Shadow Takinom army in Fear Valley
Find an alternate route into the Gothos Tower
Finish the game's Story Mode
Add 10 new different Creatures to the Creature Pool
Add 25 new different Creatures to the Creature Pool
Add all the different Creatures in the game to the Creature Pool
Refine at least 25 Creatures
Find 10 different Battlegear items
Find all the different Battlegear items in the game
Find 15 different Mugic spells
Find all the different Mugic spells in the game
Win 20 Ranked Matches
Win 50 Ranked Matches
Make 25 fully successful bonus Attacks during Story Mode battles
Make 25 fully successful blocks during Story Mode battles
Scan 20 Creatures in battle
Scan 5 Creatures in battle