Are D:OS1+2 designed as single player game with the option to have a multi player ( like baldurs gate) or as a multi player game with the option to play alone?
I played D:OS1 as single player and it was one of the best games I have ever played. But some things seemed very strange to me until I realized that it can be played as multi player (2 main characters, RPS between player characters, no pause, . . . ).
I have not played a multi player game for a very long time. The only multi player RPG (not MMOs) I have ever played was Secret of Mana.
As far as I analyzed it, it was an experiment trying to combine both. Mechanically it was a huge success even if some of the systems needed more work (char progression past a certain point, talents, perks), but all in all it was very well made. The insurmountable chasm was the writing. By making both main characters blank slates (to accommodate multi-player in the story), it relegated them to non-entities that the universe just treated as the special snowflakes du jour. Without proper context and input from the other main character it all felt token, unreal and absurd when they were trying to talk to each other.
This would've been an amazing opportunity to explore the relationship between you and the characters. That whole "reincarnated heroes" plot could've been dropped, it really didn't matter anyway, and made the characters literally the puppets of the universe or the Source. I.e. the Source creating life (it can do this, because of its healing properties), so it can save the planet from the villain-of-the-week. Since the Source isn't an organic entity, the characters feeling like puppets on a string would be LITERALLY that. The gameplay/story interweaving like this would've been grand to see. That would explain your lack of backstory, "chosen-ness", your ability to dispatch foes normal people wouldn't be able to, the characters trying to imitate life, but not quite getting it right (when trying to talk to each other), multiplayer would make more sense, the rock/paper/scissors thing would've been the Source failing to understand other points of view etc. This concept could've been explored and expanded upon and it would've been the "main story" with the dragon business being a side-thing that you have to complete in order the preserve the world.