Personally, I like the title of Last Battle already, it somehow shows exactly what happens in the book. Although the title could be literally as in the battle near the stable, I somehow think it's metaphorically, as the Narnians are battling in their minds if Aslan is true and if he is as real and great as the stories say. 

However if I were to choose a title for Last Battle, I was thinking along the lines of  The Last Fight, Two sides of Narnia, The Apes's plan, The Last king, (LWW format) The King, the Stable, and the Ape, Change in Narnia, and The Wild Lion. 

Of all those titles, I think that Two sides of Narnia, and Change in Narnia are different from the rest because they have 'Narnia' in the titles.  Many people mentioned that the books never have the word Narnia in the title, however since it would be the last book, I think it would be okay to make an exception this time.  The title, The Wild Lion, is representing the recurring phrase of 'he's not a tame lion' in LB, when the Calmorens and Shift use that as an excuse to show that their Aslan can do what he want and destroy Narnia. In fact that inspires another title, possibly The Good Lion, symbolizing that although not tame, he is good as well.  I think the title, The Last Fight, is basically the same thing as The Last Battle, so I wouldn't really recommend that one. Also similarly is The Last King, and all three titles signify Narnia's end or in the process of ending. The title, The Apes Plan, has a similar type of title to LB and SC, showing the significance of something in the book that is important and impactful. Lastly, the title, The King, the Stable, and the Ape, like LWW, is stating three major objects or characters that play important roles in the book and typically gets you interested. (I know hearing a title like LWW definitely did for me, at least!) 

I quite like the title but I’ll give a few ideas cos why not.

The False Lion

The Ape’s Aslan

The Last Loyal Narnians

Tashlan

Out of the Shadows

The Unstable Stable

Posted by: @nathanael

The Last Loyal Narnians

Sounds fitting, since Narnians had to decide which side to be on. Then the there's the dwarfs who didn't want to be on either side. "The dwarfs are for the dwarfs!"

Tashlan

I think that's stretching it a bit. The first mentioned we get of Tashlan is where Shift and Rishda are talking to the crowd at a midnight meeting, where Shift tries to say Aslan then Rishda tells him, "Tashlan."

The Unstable Stable

I guess that makes sense. Since there wasn't knowing what was inside the stable, it makes it unsettling almost.

Other better titles for the last battle I thought of were “Further Up and Further In” or “The Adventures of Tirian and Jewel”

I like the title of The Last Battle because it sounds ominous at first, like a bad thing, but on reflection is good: a permanent end to conflict. This strikes me as very appropriate for a story that seems like a hopeless tragedy for the first two thirds but ends euphorically. 

Honestly, I'm a little tired of all the title improving threads. They were fun at first but now I feel like people are just trying to come up with new titles for the sake of it.