Your dealing with sibling wars in other families, but ignores your one why?

I have been dealing with step brothers fighting step or half sisters or brothers.
It is getting worse as the parents are near death.

I see that one sister or brother will not let go of pass and accept parents death. Causing wars and so on.

So any advice on how ti deal with siblings at war.
Updates
+1 y
Why is step children or half children, brothers or sisters seem to fight more than full blooded reletives. Are they fighting for the abandon parent and blaming the child for their parents spliting up
Your dealing with sibling wars in other families, but ignores your one why?
Post Opinion