I cannot find any way to incorporate them into my combos, except for finishing combos in the air and starting them with her air down square, do the grounded versions of Nariko's square moves have any practical purpose?
This guy is a jerk : http://www.gamefaqs.com/boards/user.php?board
Grounded down square can lead to full combo and if you can connect with the second part of forward ground square it also can lead to a full combo. Second part of neutral square is used for some crowd control and ground up square is cool looking and leaves the opponent in the air rather than on the ground so its less punishable.
nariko is useless in general. shes so underpowered. i even manage to lose to the scrubbiest noob kratos players with her. she might even be worst character idk its debatable, big daddy is sometimes better off.
Since you can combo Nariko's grounded squares together a little longer than the end of time, I'd say they aren't useless. I find that nariko is a slower, more powerful Kratos. Though, Raiden is much, much faster and stronger to boot, so...
actually nariko generates ap much slower than kratos. only her triangle attacks give 30, whereas kratos can get 30 just forward squaring once. shes definately not "stronger" shes slower AND weaker. her projectile forward circles are infact so slow that you can see them from a mile away and just press counter attack to deflect them.