I've heard much about you, (playername). Come, speak with me, child...
— Holy Lord Phoenix
The Holy Nation Route is a World State Route where the player has allied relationship with The Holy Nation and having initiated dialogue with Holy Lord Phoenix that opens up the questline for HN.
After the initiation of the questline, Phoenix will tell the player to capture Moll, the leader of Flotsam Ninjas. Or Seto, the daughter of the leader of Shek Kingdom: Esata the Stone Golem.
Turning Moll in after capturing her will cause the dialogue to switch to Seto, and vice-versa. If both of them are captured, the dialogue with Phoenix hits an infinite cycle of switching between Seto and Moll, possibly due to World States dialogue of Phoenix written incompletely causing this/these loophole(s). If the appropriate conditions are achieved, it may be possible to switch to Mukai (if FB is not alive) or Flying Bull (if Mukai is not alive) or Esata as the target.
Though it appears that the player can capture Emperor Tengu and Tinfist and have special dialogues when turning in, which could possibly mean that if the dialogue was completed they would've also been included to this route.