Another of Eko, this time interacting with Lunaci.

As previously mentioned, Eko was designed with video gaming in mind as the party's mage character. Lunaci would also be a member you could recruit into your party, acting as the party's speedster, and his interactions with the other characters would change depending on when and how you get him to join your party.

No matter when he joins though, upon meeting Eko he doesn't really like her. He finds her to be annoying, but in battle they can still have a laugh that they're immune to ground attacks because flying.

Though Eko only gains immunity to ground attacks after the player gets Frus in the party AND after equipping the dragon with a battle harness. Otherwise they appear in battle on the ground together rather than Eko riding Frus.
Lunaci has immunity by default, except when under the status condition 'new moon' which eliminates his ability to fly, gives him a speed penalty, sets his mp to 0, and gives him a 33% chance of falling asleep at the start of a battle.