There are some special conversations in the game. This consists of some recruitment ones, battle conversations, and ones that require the "talk" command. At the moment the list only includes Part 2/3 conversations as I have not compiled a list of Siegfried's Story (Part 1) conversation. Sorry about that.

[B] = Battle, [T] = Talk Command, [V] = Village

Special Conversations*:

Ace - Noris [Ch11] [B]
Anakin - Noris [Ch11] [B]
Kevin - Noris [Ch11] [B]
Anakin - Nayr [Ch11] [T]
Anakin - Eduardo [Ch11] [T]
Anakin - Logan [Ch11] [T]
Kelik - Zekiel [Ch13] [B]
Cia - Tamiko [Ch14] [T]
Kevin - Tamiko [Ch14] [T]
Anakin - Soldier [Ch14] [T]
Lirin - Lena [Ch14] [B]
Anakin - Lena [Ch14] [B]
Kelik - Eric [Ch15] [B]
Anakin - Eric [Ch15] [B]
Tekun - Althares [Ch15] [T]
Kelik - Tekun [Ch15] [T]
Lirin - Inanna [Ch16] [T]
Mark - Gordon [Ch17] [T]
Mark - Inanna [Ch17] [T]
Mark - Shuuda [Ch17] [T]
Tristan - Anakin [Ch17] [B]
Zoro - Kelik [Ch17x] [B]
Howard - Kelik [Ch18] [B]
Howard - Anakin [Ch18] [B]
Howard - Siegfried [Ch18] [B]
Cia - Howard [Ch19] [T]
Anakin - Rex [Ch19] [T]
Kevin - Rex [Ch19] [T]
Rex - Cid [Ch19x] [B]
Mark - Sai [Ch20] [V]
Zane - Ben [Ch20] [B]
Zane - Kelik [Ch20] [B]
Zane - Siegfried [Ch20] [B]
Ben - Roman [Ch21] [T]
Ben - Roman [Ch21] [B]
Siegfried - Leopold [Ch21] [T]
Eligor - Roman [Ch21] [B]

* I likely forgot some and may have put one in that doesn't actually exist, please excuse that if it happens. In addition, talk convos may only go one way in some cases, so only one character can talk to the other (usually if it's two allies its both ways though).