User blog comment:SayuriDarling/The Mark of Athena Official Discussion/@comment-5078063-20121118153927/@comment-65.95.224.187-20121121213115

Screw that stuff, the only obvious reason Nico isnt among the seven is that he is too powerful. And would likely have overbalanced the team.

His necromancy, shadow travel, geokinesis coupled with his swordplay. It would have been hard for Rick to downplay Nico's abilities