If you have been given a copy by your friend then you are not missing out on the DLC. There is only 1 Source Hunter DLC pack in the Digital CE. Your friend has it on his account most likely as he bought the pack.
If you play together with your friend you will both benefit from the items the DLC gives, if both players have the DLC then in a multiplayer game there would only be one player with the items as these are unique lore items in the Divinity universe and you are joining his story (as the host) when entering an MP game created by him, so to speak.
Yes ? We bought the game in half . That is, I paid for one game more than it is sold.
