Ok im going to type this off the juu of my head so if its bad don't have a hissy fit!!:P
I always wonder what would happen if Sirius didn't die so here goes nothing!!
It all happend so quickly.Harry was helping Nevile up when Harry saw Sirius and Bellatrix Lestrange.
She was winning laughing as ahe threw spells at him he faught back but was weak.Then she hit him with crucio.It hit him in the chest and he started to fall backwards into the arch way Lupin,Tonks,Mad eye and a few others all ran with Harry to stop Sirius falling his head and chest where in the archway but wewe couldn't them at the back.It was so strange wewe could hear Sirius screaming in pain.Harry and the others took his arms and legs and pulled.Harry had tears in his eyes so did Lupin and Tonks.
They pulled so hard that Sirius came back through the arch way.His face was sratched badly,verybadly.His chest and shoulders where also badly cut but he was alive all Harry could do was cry and hold Sirius in his arms Lupin and Tonks held each other .This didnt last long Bellatrix was not happy she ripped the left sleve off her dress and called Lord Voldemort to the Minstery.Harry,Tonks,Lupin,Mad eye and all the others Ron Nevile,Ginny Luna the order got ready to fight again only this time they had Dumbeldores help!Harry could see Lord Voldemort was angery to see all that had survied the fight but alisema nothing."Tom I didn't expect to see wewe here to night"Dumbeldore said."Dumbeldore!Why aren't wewe in hiding?I should hav expeted wewe to come to Harrys rescue and ofcorse Siruis Black i knew wewe would come!"said Riddle.But Sirius didnt hear this maoni he was alive but unconscios.Harry knew Riddle would want to kill Harry so that meant he would hav to let go of Sirius.Lupin knew this as well he alisema to Harry in a whisper"We'll look after him Harry.Go on get ready you'r the onlyone he want.Go on let go of Sirius...Now!".It took all Harrys strength to let go but he did it!
Now all he had to do was..beat Lord Voldemort!!