Will Sauron Be Recast in The Rings of Power Season 2?
To the surprise of few, The Rings of Power Season 1's finale confirmed the prevalent fan theory that Charlie Vickers' "Halbrand" was actually Sauron in disguise.
However, after influencing Celebrimbor to forge the three Elven Rings of Power, he has to depart Eregion because of Galadriel figuring out his identity, and ends the season standing over Mordor. This creates a plot problem, as there are sixteen more Rings of Power to make (those which later went to Dwarves and Men), and Sauron was supposed to participate in their creation.
The solution to this problem might lie in an Easter egg, used by scriptwriters. While advising Celebrimbor, the chief Elven smith, Sauron at one point responded to the Elf's praise with the ominous line: "Call it... a gift" This quite pointed use of the word "gift" is an allusion to Annatar – the disguise which Sauron used to infiltrate Eregion in the book canon of J.R.R. Tolkien's legendarium.
"Annatar" is translated as "Gift-Giver" or "Lord of Gifts" from the Elven language. These words might be an Easter egg and nothing more, or they might tease Sauron's new form, which he never assumed in Season 1, but which he might use later, now that he knows what approach is optimal for ingratiating himself with Celebrimbor.
The evidence pointing towards the latter goes beyond a single phrase. The Rings of Power co-showrunner Patrick McKay described Sauron's Season 2 arc as "a canonical story" while also admitting the villain's next chapter was probably what some fans were expecting from Season 1, and fans could only expect the story of Annatar influencing the Elves. Meanwhile, Charlie Vickers acknowledged in an interview: "We know Sauron takes on different shapes in this era... Maybe we're going to do those things."
However, if that is true, the question of a new actor for Sauron arises, given that Sauron is unlikely to use the same form for interacting with the Elves anymore. Theoretically, of course, the writers can use the plot point of Galadriel being unwilling to directly say that Halbrand was Sauron all along, instead of just issuing a general warning not to trust Habrand. But given hints above, Sauron appearing in a form completely different from Halbrand seems more likely.
As Sauron still wears the same face when returning to Mordor in the final scene, and Charlie Vicker's performance was generally praised, that might mean that the "Halbrand" form will remain the "default" one, but Charlie will have to share Sauron with another actor.