One of the more endearing debates of the Zelda world is the wizard who put Zelda into a deep sleep in the events that lead up to Zelda II: Adventure of Link. In this theory, I will lay out all the evidence and draw a logical conclusion, based not only on the evidence provided but also on my extensive knowledge of Hyrulian history and deep insight into the events which preceded this tragic event.
A servant of Ganon, the primary antagonist of the story and one of the most powerful beings in the Zelda folklore
An independent trouble maker, which may seem like a “Deus ex machina” solution, but hey, these things happen in fantasy
Agahnim of LttP, a powerful dark wizard who assumes the role of the secondary antagonist before it turns out that he is the alter-ego of the demon Ganon
If we look at the evidence, there are three possible answers to the question at hand. Either the Wizard was a servant of Ganon, or it was and independent troublemaker, or even Agahnim of LttP. The latter, however, is unlikely because, at the end of each wizards’ tale, they died. This Wizard of natural causes, and Agahnim at the hands of Link. The only evidence that could corroborate that the wizard was Agahnim is that they both minds controlled those around them. The Wizard, the Prince, and Agahnim the Palace Guards.
However, as for whether the Wizard worked for Ganon or not, there is no set evidence either way. After Zelda fell victim to a deep sleep, and the Wizard died, rumors spread across the towns of Hyrule that he worked for the King of Evil, but those are only rumors and not significant proof. Thus, the question of whether the Wizard worked for Ganon is unanswered.
Conclusion- My conclusion is this, that the Wizard was not Agahnim, but a mysterious man that was under direct control of Ganon, much like Agahnim was. I say this because Ganon harbored a known hatred of Zelda after being foiled by her in LttP and the Oracles Series (according to our timeline). It would only be logical that it’d be he that would strike against her and put her to her long slumber.