Yes! They are half brothers as Willowpelt is their mother. Darkstripes father is Tawnyspots and Greystripes father is Patchpelt.
Yes, graystripe and Darkstripe fight when Graystripe sees Darkstripe feeding Sorrelkit death berries. It's in book 6
Darkstripe dies before he can have a mate in book 6 the darkest hour. He died in the battle of Bloodclan killed by Graystripe
He doesn't show any respect because Darkstripe is loyal to Tigerstar and Tigerstar hates Graystripe, Firestar, etc. Also, Darkstripe is pretty much rude to everyone.
Graystripe killed Darkstripe to protect Firestar, as Darkstripe was a traitor working for Tigerstar and attempting to harm Firestar. Graystripe recognized the threat Darkstripe posed and took action to ensure the safety of his leader and Clan.
Darkstripe attacked Firstar (or Fireheart at the time I think) during the BloodClan invasion, since he'd joined BloodClan's side after Tigerstar died, and Graystripe came to Firestar's aid and killed him. So in all, Graystripe killed Darkstripe.
Graystripe.
Yes, She is related to Graystipe, here's how:Willowpelt is Dappletail's daughter,And Willowpelt is Graystripe's mother, (Patchpelt is his father and Longtail is his half-brother)So Dappletail is Graystripe's grandmother!
Yes, he does. Tigerstar orders Stonefur to kill Graystripe's kits and Stonefur refuses, then Tigerstar orders Darkstripe to kill him, but Darkstripe is defeated, so he gets the help of Blackfoot and they kill him. This happens in "The Darkest Hour", the last book of the first series.
Graystripe returns in power of three:the sight
Darkstripe is a large, sleek, dark gray tabby with black stripes and amber eyes.
Graystripe is a gray tabby with a darker stripe running down his back, starting at the back of his head to his tail-tip. greystripe is a nebelung,not a tabby
Graystripe returns in The Sight, in Chaper 10.