It’s someone who will die for you and someone you’ll die for.
Someone, you’ll trust to never betray you and someone you’ll never betray.
Someone you know always loves and cares for you and will have your back in any case.
Someone who’ll stand by you even if the whole world is against you.
Someone who’ll motivate you to be stronger and better,
Not just because of yourself, but because of your love to them,
because you want to be strong, in case they ever need you. I think it’s a blessing to have siblings and I’d feel like a homeless person if I didn’t have one.