Is it okay to want to strangle my brother's kids?
Have you talked to your brother about them?
He is a terrible father and he doesn't deserve a family
Children can be difficult to handle sometimes but murdering them is not the answer. There are better ways to manage children that don't require hurting them and that won't end with you in prison.
These kids are a pain in the butt, I hope he will eventually come to his senses.
Have some more patience, they are only kids after all. Try setting some boundaries with your brother and enforce more rules to get them under control. Children should be protected, so be kind with them.