Narcissist help

My mom is married to a man I believe to be a narcissist. We have basically no relationship. We truly cannot stand one another. My mom however is a saint. Currently she has had a stroke and the whole ordeal has been a nightmare dealing with her husband. Any advice or tips on how to communicate or navigate a Narcissist? My mom will most likely be paralyzed the rest of her life so this whole situation is just horrible. I know I can only control my actions and what I can do, is there anything that you've found to be helpful. I am a fighter and that has never worked in the past so my next skill set I have is to walk away and I can do that with him but I cannot do that to my amazing mom and leave her with him. Btw she is madly in love with him and has a history of abusive marriage and relationships so she is never leaving. My husband is also just perplexed as me on what to do now and he adores my amazing mom. Everyone doesn't like him but because my mom does everyone tolerates his behavior. My mom shuns anyone for going against him.