User blog comment:SayuriDarling/The House of Hades Official Discussion/@comment-24065371-20131018135727/@comment-24065371-20131019160633

Percy was concerned about how rapidly Nico grew in power, he notes this during being informed of shadow travel, and expresses shock at Nicos power when he banished the King of Minos. Percy however has never been on the border of confronting a powered nico, nico is vastly stronger now and unlike percy jason has been threatened twice by a more mature nico for touching him and after learning nico's secret,

who is stronger out of percy and jason is debatebly, jasons powers can be used without water while percy has difficulty when not near a water source it drains him much faster and he has alot less control, though if percy did follow the path of manipulating water within people then he would be stronger.

Nico can use his powers anywhere on the ground he does not require and water source or open terrain, he is also the most skilled in using his abilities due to his training with the deceased,