Thanks to a recent developer update from Toby Fox himself, Deltarune Chapter 3 seems to be right around the corner. Chapter 1 was first released in 2018, with Chapter 2 following a few years later in 2021. Chapter 3 is a long time coming, and its predecessors certainly made it a tough act to follow. On the other hand, they also gave Deltarune Chapter 3 is the perfect opportunity to do just that.
Both chapters of Deltarune have been well received and there is still a long way to go before the game is completed. On the road to the full seven chapters, chapter 3 would be a good time to start removing loose ends. Although there is no solid picture of the whole story yet Deltarune it will look like, a potential candidate for the final boss of chapter 3 could provide the perfect climax for the first half.

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Chapter 3 Deltarune has the perfect candidate for a final boss
Chapter 3 Deltarune has big shoes to fill
Despite being a sequel to Undertale, Deltarune it is a distinct subversion compared to everything that came before it. This works to its advantage for the most part, and each of the new characters it introduced has been a blast in its own way. Deltarune it didn't sag on the gameplay front either, with its combat system receiving massive praise right from the start.
In accordance with a precedent set by Undertale itself, DeltaruneHis boss fights became a big part of that appeal. Similarly, the boss battle of each chapter so far has been a solid ending in itself. In addition, each final boss sufficiently closed the themes of its respective chapter, and a character could fulfill this role to impressive effect.
Deltarune started a definite trend with the final boss battles
Chapter 1 of Deltarune ends with the players facing the King, who is one of the de facto rulers of the Kingdom of Cards. Of course, the Kingdom of Cards is only a section of the wider world, but working within this somewhat limited space rarely caused problems for the game. Also, maybe it helped Deltarune to give a better shape to the possible end of this first arc.
Chapter 2 of Deltarune followed suit closely, with players now tackling the Queen as the final boss. It is unclear whether the King and Queen are on good terms or not at this point, but their relationship is clearly established otherwise. If Chapter 3 were to continue this trend, then there is an obvious way forward.
Chapter 3 Deltarune can turn the story of the game on its head
Assuming Deltarune Chapter 3 uses an existing character for its final boss, Lancer is definitely the best candidate for the role. As the child of both the king and the queen, Lancer can significantly carry the torch he has lit in previous chapters. More importantly, however, the Lancer has an established relationship with the player and their party. Lancer started out as a minor antagonist but became a tentative ally. Lancer's role as comic relief made this seem almost inevitable, but Chapter 3 may continue to undermine that dynamic once again.
Chapter 2 has already thrown a few players for a loop, bringing Noelle to the fore when she had previously been a background character. Lancer has always been a bit more important than the average background character, but a main antagonist role would definitely take him to the next level. In fact, Lancer's ties to the early half of the game would make him the perfect character to bring this chapter from Deltarune to the end.
Lancer going from comic relief to final boss wouldn't just be possible; it would also be effective. Lancer's relationship with the King and Queen already makes him a likely option, but his friendship with the main characters is a potential source of drama that's just too good to pass up. While it's possible that Chapter 3 could go for a completely different option or simply introduce a new character like Chapter 2 did with Queen, capitalizing on the story setup so far seems like the perfect way to take Deltarune in the future.