WotC has posted a 19-minute video telling you 'everything you need to know' about Vecna: Eve Of Ruin.
- Starts at 10th level, goes to 20th.
- Classic villains and setting, famous characters, D&D's legacy.
- Vecna wants to become the supreme being of the multiverse.
- Vecna is a god of secrets and secrets and the power of secrets are a theme throughout the book.
- A mechanical subsystem for using the power of secrets during combat.
- Going back to Ravenloft, the Nine Hells, places where 5th Edition has been in the last 10 years.
- It would be a fun 'meta experience' for players to visit locations they remember lore about.
- Finding pieces of the Rod of Seven Parts, pieces throughout the multiverse.
- Each piece in one of seven distinct planes or settings.
- Allustriel Silverhand has noticed something is wrong, puts call out to Tasha and Mordenkainen, who come to her sanctum in Sigil.
- The (10th level) PCs are fated to confront Vecna.
- Lord Soth and Strahd show up. Tiamat is mentioned but doesn't appear 'on screen'.
- Twists, turns, spoilers.
- It's a 'love letter to D&D'.