well in order to complete the monster arena tasks you gotta get at least 1 but to unlock the mega creation NEMISIS you gotta capture 10
Place found are right at the end of the cave where the telepod is and in a cave that has a green tinge behind the big rock that slighty cover the view of a chest!!
be warned Karma inflicts damage based on the amount of people each character has slain, regardless of stats!!!
TSA