This is the theory that the true identity of the Black Knight is Zelgius—a Begnion general who aids Ike in the battle against Daein. If you don’t know who Zelgius is, his image is here.
(May contain spoilers)
[Since the sequel, Radiant Dawn, has now been released, and details have been proven correct or incorrect, I have added some Radiant Dawn-related comments that I will put in squared brackets. Like this.]
The basis of the theory, which I doubt the theory would exist without, is that Zelgius has unused character data within the game. Zelgius and the Black Knight have identical growths, affinity, class (actually the Black Knight has his own class, but they are both Generals) and weapon ranks. Also, Zelgius has similar (but not identical) stats as the Black Knight. Additionally the Black Knight’s battle theme is labelled as BGM_BTL_ZELGIUS1 internally.
Some argue that the stats are meaningless, simply for being unused. However, despite not appearing in battle, Nealuchi, Caineghis, Greil and Sigrun have realistic stats, so why not Zelgius? Another thing to think about is why does Zelgius have data in the first place? It’s possibly Intelligent Systems wanted him to make an appearance, but scrapped the idea later (maybe if you saw his stats, you’d catch on easily…).
Even if the stats don’t prove a thing, they did make people aware that Zelgius was actually a good candidate for the Black Knight. I think the best way to see is to run through most of the known facts about the Black Knight.
1) The Black Knight somehow obtained Goddess-blessed armour for himself and Ashnard.
Since Begnion is the land of the Goddess’s followers, it is likely that the armour originated from there. Zelgius resides in Begnion so perhaps he would know about the armour or how to get it.
[The armour’s origin was not discussed, but it is implied that it belonged to the army of Goddess Yune. Ashera’s soldiers have golden armour, so perhaps Yune’s army had black armour. Since Ashera’s army was successful, perhaps they stole some armour from their enemy (in the original battle they probably didn’t have any Goddess-blessed armour). The swords Ragnell and Alondite, however, are stated to be of Begnion origin, and it’s likely that were under the possession of Sephiran (Altina was the swords’ owner and she was Sephiran/Lehran’s wife).]
2) The Black Knight was taught in the skills of fighting by Greil.
Greil taught the Black Knight around 15 years ago (an approximate number), so if the Black Knight was around 15 years ago at that time, he would be around 30 years of age now. I’m not too good at judging the ages of people, but Zelgius looks like he is around 30 years old.
[It is discovered that the Black Knight is Branded, so the age discussion is moot.]
Also, perhaps Zelgius’s prowess in battle was due to Greil’s training. It could be said that there are few youthful fighters who could match Zelgius’s success.
3) The Black Knight did not attack Sephiran at the port town.
Some believe that the Black Knight held back solely because he didn’t want to provoke Begnion into attacking Daein (Sephiran is the prime minister of Begnion).
However I am inclined to believe that it is also partially because the Black Knight (assuming it’s Zelgius) knows Sephiran deeply. Perhaps he is working for Sephiran, or is an ally. When Sephiran tells the Black Knight to spare Ranulf, it sounded almost like an order, and the Black Knight obeyed almost as if he held loyalty to him.
[The Black Knight was indeed working for Sephiran.]
4) The Black Knight despises Laguz.
One consequence of this is that the Black Knight cannot be a Laguz. Any theories about the Black Knight being Deghinsea, Giffca or other Laguz characters practically fall apart here. Unless he was lying of course (but his hatred seems real enough).
We know that Begnion has a history of hatred towards Laguz (as can be seen from the Laguz slavery). Since Zelgius is a citizen of Begnion, perhaps he picked up their way of thinking? Then again, it seems Daein is more keen on racism against Laguz.
[As stated, the Black Knight is a Branded and thus dislike his Laguz ancestry.]
5) The Black Knight is a strong character.
What this means, is that the person under the armour must be strong. Ranulf mentions that he is amazed by the speed that the Black Knight attacks. Since Zelgius is a general, he will be used to wearing the Black Knight’s armour.
[The amazing strength is also likely due to the Black Knight being Branded. It was stated that the Branded are stronger than ordinary Beorc.]
6) It seems the Black Knight is a handsome character.
Judging by his voice anyway (well his Japanese one at least), I would associate the Black Knight’s voice (distorted as it is) with a tall handsome-looking fellow. I’m not a good judge of appearance, but I think Zelgius fits that description. This might sound trivial, but I thought it was important—it means the Black Knight probably isn’t some rough or ugly person.
[Zelgius and the Black Knight also have the same (Japanese) voice actor.]
7) The Black Knight and Zelgius never appear at the same time.
Of course, other people would qualify, but the key point is that so does Zelgius. Some note that Zelgius appears even after the Black Knight is defeated or “killed”, which they use as evidence against the theory. I say “killed”, because I’m sure he doesn’t die. When you defeat the Black Knight, he fades around from the map. However not all characters die when they fade away—Shinon is a good example of this.
As for being crushed by the rubble… In real life, if a castle collapsed on somebody, chances are they’re dead. However the Black Knight has blessed armour that could completely or partially protect him from danger. Also you have to bear in mind this is a game/RPG, where it’s not uncommon for characters to return from what seems like certain death. It’s a cliché, which Fire Emblem is full of.
[In the Japanese version, the Black Knight survived because of a malfunction of the warp powder. He stated that during the battle only his spirit was warped inside the castle, and not his body. Since his body is elsewhere, that means it can’t be inside the castle to be buried. What a cheap get-away… The English version doesn’t bother to go into any details other than he survived.]
The biggest hint that the Black Knight survived is that his body was not found after the incident. Again this is a game, so I doubt they missed a spot or just went past his body. Either he escaped himself, or somebody helped him. The Black Knight cannot die, because too many questions need to be answered (Fire Emblem is a popular series, so I doubt they will leave them unanswered). With Radiant Dawn being confirmed as a sequel (and the game logo sporting Ragnell and Alondite), it’s very likely that the Black Knight will return in some form.
[Unfortunately (?) the Ragnell and Alondite logo was dropped.]
So assuming the Black Knight/Zelgius didn’t die, it would make sense for Zelgius to make an appearance after the decisive battle to fool the players. Which he does. Even if he was injured, perhaps there was enough time between the battle and the finale for him to recover (fully or partially). That or maybe he had a helping hand in the form of Sephiran?
All in all, I think Zelgius manages to fit into all the facts rather nicely.
Another thing is why was Zelgius introduced into the story at all? His appearances were short and forgettable and he wasn’t too important story-wise. Even if Ike did need a Begnion general to help him, he didn’t have to consult personally with him or it could have been a generic NPC (admittedly, that would be a bit of a cop-out). I would be surprised if, when Zelgius offered to help Ike, you didn’t expect him to become a playable unit yourself. The fact that he/the game doesn’t let you use him seems awfully suspicious to me… Again, perhaps it was to hide his stats or something, or so he wouldn’t have to go suspiciously missing during the battle with the Black Knight.
Despite everything, the theory is not without its faults.
The fact that Zelgius has such a small role might render the whole Black Knight mystery an anti-climax. Imagine getting near the end of Radiant Dawn, when the Black Knight reveals his identity as Zelgius. I doubt even Ike would remember who Zelgius was, let alone the player! Despite that, I think a small role is better than no role—the theory that the Black Knight is hollow (so Greil was teaching a suit of armour?) or somebody not introduced (this would have no difference other than Zelgius already featured in one game).
[Zelgius had a much larger appearance in Radiant Dawn. Unfortunately, Ranulf kind of spoils the surprise a little too early…]
My own attack at the theory is that how on earth could somebody possibly manage a double life of being a famous Begnion general and an infamous Rider of Daein? Of course, the Black Knight had Warp Powder, which could explain how he could be at both Begnion and Daein at the same time. Still I think it would be a tricky stunt to pull off and Zelgius would have to be a pretty darn good liar. Now that I think about, his eyes do look a bit sinister, but it’s probably my imagination…
[The double life is possibly even more wild, seeing as he fights in the war, in Radiant Dawn, as both Zelgius and the Black Knight!]
So that’s basically most of the “Zelgius theory” summed up. I probably forgot some minor notes, but I think I got most of the important ones. Even if you don’t believe the theory (I’m not saying you have to), you have to admit it’s one of (if not the) strongest theories out there. Hopefully when Radiant Dawn is released, we’ll see how accurate this theory is… I’d bet a lot of money on it :).
[By the way, in case it wasn’t obvious by now. Zelgius is indeed the Black Knight. As if there was any doubt…!]