Well, as of July 2023, the DLC for Elden Ring hadn't been fully released yet. But generally, it's likely to expand on the lore of the Lands Between. It might further explore the origin of the demigods, their relationships, and the secrets of the Elden Ring itself. Maybe we'll get more backstory on characters like Malenia or Radahn.
In the Elden Ring DLC, there are approximately four story bosses. However, this can change depending on different gameplays and hidden challenges that might reveal additional bosses.
A Samurai build can be great for the story. It starts with good stats for both melee combat and some ranged attacks with the bow. The katana offers fast and stylish combat which is fitting for the various encounters in the story. You also get some decent armor early on that gives a good balance between protection and mobility.
We could see the expansion of the existing storylines. For example, the fate of some of the bosses or characters that were left a bit open - ended in the main game. There might also be new areas with unique stories related to them. Like, perhaps an ancient civilization that was only hinted at in the main game will be fully explored in the DLC.
Personally, I think it's better to play after the main story. You get to fully immerse in the main plot first and then expand your experience with the DLC.
Sure. Usually, game developers make DLCs somewhat independent of the main story's completion. But it might have some references or benefits if you've finished the story.
A Confessor build is ideal for the story. It offers a mix of melee capabilities and access to incantations. As you go through the story, you can choose to focus more on melee combat with swords and shields if you like a more up - close and personal approach, or you can develop your incantation skills to deal with enemies from a distance. This build allows you to adapt to different parts of the story and the challenges they present.