A deadly dose of malignance is overtaking Sanctuary: a new Season Journey, Questline, Boss, Dungeons, Battle Pass, and more are coming with the first Season of Diablo IV on July 20.
To participate in Seasons, a new character must be made on the Seasonal Realm. You do not need to purchase a Battle Pass or any add-ons to play the Seasonal content, but you must have completed the campaign on either the Eternal or Seasonal Realm with at least one character.
This makes no sense.
How am I supposed to clear the campaign on the seasonal realm if I first need to clear the campaign on the main realm? Why did they word it like this?
I know, but why would they even mention completing the campaign on the seasonal realm if you can't access the seasonal realm? Why not just leave it as "complete the campaign on the eternal realm"?
You can start a seasonal character without completing any campaign. What you can't access is the seasonal content. This starts after you complete the campaign - so you won't see malignant creatures or the quest line or gems or whatever until you've completed the campaign.
because it is accurate to how things actually work
Because not everybody has been obsessively playing this game since launch. Some might come back to the game after dropping it 1/4th of the way through the campaign. Some have just bought the game now. They will want to know that they can just start a seasonal character and complete the campaign on it.