My question is with a secondary character what carries over from the first for instance do I have to do the questline again (questline completed on first) and how does it works with the season pass?
As on the Eternal realm, Seasons allows for the renown rewards such as skill points, potion counts, and paragon, to transfer to your second character.
You have to option to bypass the campaign during character creation as long as you completed it on the seasonal realm, or logged into your Eternal character that has done so.
Not exactly what I mean I have one seasonal character that did the seasonal questline and I want to make a second seasonal character what does that second character inherit from the first one on the seasonal realm? I mean does he/she need to do the seasonal questline again or can I freely interact with the hearts without the quest also how does a second character works with the battle pass?
I don’t have the answer to that, but I do believe the seasonal questline opens it for all characters.
Create a new character if you already have not and test it out. You can go straight to a malignant dungeon and test it out.