Lately I've been having the urge to wish my siblings were never born.
That is a little extreme, why would you wish that?
I don't really like them.
If you do not like them, just do not be around them. You do not need to wish that they do not exist. It is a little bit too extreme.
I don't like them. I didn't ask to be born so they deserve it.
It's understandable to have issues with your siblings when growing up and such. But going to extremes and wishing they were never born isn't the right way to go about things. If you are having problems talk with your parents or your siblings and hopefully to work something out.