It might be available in the next version.
Faker::Cosmere.aon #=> "Rao"
Faker::Cosmere.shard_world #=> "Yolen"
Faker::Cosmere.shard #=> "Ambition"
Faker::Cosmere.surge #=> "Progression"
Faker::Cosmere.knight_radiant #=> "Truthwatcher"
Faker::Cosmere.metal #=> "Brass"
Faker::Cosmere.allomancer #=> "Coinshot"
Faker::Cosmere.feruchemist #=> "Archivist"
Faker::Cosmere.herald #=> "Ishar"
Faker::Cosmere.spren #=> "Flamespren"