Shiva's character is just being used to insult, accuse, shout at, beat up and throw out other characters. That is all he is doing now.
Despite not knowing what happened for the last 9 years, he confidently passes judgment on others and behaves quite abrasively with them. He isn't even trying to recall his memories as if he doesn't care. Not that anyone else does either. They planned another party while he is in this condition and his wife is made to live elsewhere. Not to mention the kids' confusion hasn't been resolved.
I'm actually glad Gautam told him Krish has just as much right on the house, because Shiva's high-handedness is starting to irk. He has no clue what any of them are going through. Why is he even involved in family issues in his current state anyway.
The way Shiva talked about Raavi in the segment was extremely rude. This is when he believes she is Dev's wife and the mother of his child. She is someone he thinks to be his sister-in-law but is still so disrespectful towards her. Why no one is correcting him on that is a mystery, but he really isn't looking good acting like this.