Name: Reddas (Zecht)
Japanese name: レダス （ゼクト）
Seiyuu: Takayuki Sugō
Voice Actor: Phil LaMarr
Quick note — the FF Wiki lists his full name as Foris Zecht, which is apparently in the Scenario Ultimania, but I can’t find it in said book. Of course, I don’t know Japanese, so hell if I know which page to look on (it’s not in Reddas’s main character profile). If anyone knows the deal, please drop me a line and let me know; I’ve just listed Zecht above in the meantime.
(Also, Reddas is apparently 33. Nabudis apparently aged him a lot, like what the hell.)
Anyway. Reddas doesn’t appear until the last 15~20% of the game, but he manages to make a big impact with the little screentime he does have. He is introduced as a mysterious visitor to Draklor Laboratory, arriving and wrecking the place just before the party does and fighting against Dr. Cid with them. It turns out he was making a bid for the Dusk Shard Dr. Cid held, wanting to get it out of Archadian hands, but the attempt failed, and he returns to his home of Balfonheim with the party. Reddas, it turns out, is a sky pirate, and has over the past two years cleaned up the place, gaining him both friends and foes.
While the party investigates Cid’s lead at Giruvegan, Reddas explores other avenues, namely the Ridorana Cataract. He locates the Pharos and joins the party as a guest, which is really helpful considering how ridiculously hard the Pharos is. When they reach the top of the tower and find Dr. Cid and Gabranth, Reddas’s real identity comes out: he used to be Judge Magister Zecht, who led the assault on Nabudis two years ago for the sake of the Midlight Shard. The ensuing destruction caused him to abandon the Judges and Archadia.
When the Sun-Cryst becomes unstable in the face of the nethicite Dr. Cid brought, Reddas takes the Sword of Kings from Ashe and uses it to destroy the nethicite, sacrificing himself in the process. Back in Balfonheim, his team comments that he was looking for a place to die this whole time.
Like I said above, Reddas is a hell of a character for a guy who’s in the game for such a short period. I love that we actually get to see someone on the Archadian side who really regrets what happened at Nabudis; it adds a lot of dimension to the Empire and the Judges. The reveal of his identity comes at a moment in the plot where a lot is going on, so it’s a little much at the time, but it’s still a good twist all told.
I also think Reddas is a necessary foil to Ashe, because it’s at this point that she really needs someone to tell her that no, nethicite is terrible and you should never, ever use it. You need to remember Nabudis. Actually going to the Necrohol of Nabudis is totally optional, after all; some players will never see those horrors for themselves. It needs to be in the plot to drive home why it would be terrible to turn Archadia into that kind of ruin in the name of revenge. (I actually took Reddas with me to the Necrohol and the Deadlands in my last playthrough, but unfortunately he has no lines. It would have been a nice addition, but it also would have ruined the twist, so I get why there's nothing there.)
And, yeah, Reddas is a great guest character. I have no idea how you would climb the Pharos without him. In IZJS he has Arise and Holy, which saved me from certain death many, many times.