If I for example want to start a youtube channel and the content is gaming and I play a game that contains something haram, like music and later I post that videoon youtube. If I put a warning in the video for haram content so people know, but despite that people watch it, do I take the rights of those people who watch that video or are they responsible for their own actions despite the warning I put for haram?
Both of you (who helps publish something haram and the one who consumes it) would be responsible and take rights for it, even if you warned them. Actually, if you publish something that you know is haram, and you know for sure that only non-Muslims who won't care much about the warnings are going to consume/watch it you will take rights for them as well (as according to Ibn Abi Shaybah and the majority of Ulama, Sharia applies to non-Muslims as well).
The prophet said: "I seek refuge with You [Allah] from the misdeeds of shaytan and his encouragement to associate and that I bring evils on myself or bring it on another Muslim" (Sahih).