I just picked up the game and have been playing casually. I was playing last night and I played a Yog-Sothoth spell (sorry, don’t have my cards in front of me) on my turn that forced my opponent to sacrifice a character. In response he played a Hastur card that took control of one of my characters and then sacrificed it to fulfill my spell. It seems legit but I wanted to double check to make sure we were playing that interaction right.

Thanks.

There is no "chain" or anything like in Magic. Actions get resolved, then the other player gets a chance to take an action. Only things labeled "disrupt" or "forced response" can interfere with timing.

So when you played a card that told your opponent to sacrifice a character, there is no window for him to play a card. He must sacrifice a character.

Then. after that reaction is fully resolved, it will be his turn to do something, and he could take control of a character using his card.

Good to know. Thank you for the response.