Heaven's Feel: Ending
Rin finally manages to face Sakura in the large cavern, and while they talk for a bit, the conversation ends quickly with Sakura summoning various shadow beings. Rin brings forth the gem sword and cuts them down. Sakura summons more, and yet Rin cuts those down as well. With effectively limitless power Sakura is infuriated and cannot understand how Rin can compete with her. Rin informs Sakura that even though she would never run out of power, she is still limited by magic circuits and thus can only bring forth things that are of around 1000 units of power. The gem sword takes power from unlimited other dimensions and so she is able to match that power. This frustrates Sakura even more, but Rin knows one unfortunate fact, while Sakura summons the shadows at a whim, Rin has to physically exert herself to kill them. While she intended to wait for Shiro, she'll slow and make a mistake soon.
So Rin decides to play her hand and throws the sword at Sakura while invoking a spell, causing it to explode. While it's not any sort of threat to Sakura, she's inexperienced at fighting and flinches. Rin then rushes Sakura with a dagger. Sakura sees Rin coming and prepares herself to finally be done with everything, but then Rin is the one who ends up stabbed not Sakura. Rin embraces Sakura with warm smile on her face. Even though she had always been cold, and talked heartlessly... in the end she couldn't bring herself to kill her sister. Sakura finally realizes that Rin really did love her all along.
Towards the entrance of the cavern, Rider faces Saber. Shiro distracts Saber just long enough for Rider to use her noble phantasm, but Saber also manages to counter it with hers at the same time. Saber's is of course far more powerful, but Shiro calls forth one of Archer's phantasms and they finally overwhelm Saber. While Saber is incapacitated, she isn't done for, but finally Shiro deals the death blow himself. The girl who had once sworn herself as his sword is no more. He had decided his path, and he will save Sakura no matter what. Rider however can't move either, and Shiro goes on ahead without her.
At the summit of the grail alter deep within the cavern, Shiro finds Sakura standing before the limp body of Rin, however the situation had changed dramatically. Sakura rejects the command spell that had bound her, but it mercilessly assaults her and won't let her escape. She pleads for Shiro to run, but he has made up his mind to save her. He's able to project one more weapon before he's finished, and summons Rule Breaker: Caster's weapon, and breaks the contract with the eighth servant. Sakura faints but is otherwise fine. It also looks like the magic crest of the Tohsaka family will not let Rin die so easily either, and she'll be alright. But things don't look so good for Shiro.
Normal End: Cherry Blossoms' Dream
Shiro is spent. He can hardly even remember why he's in the cavern, or what he's supposed to do there. A servant appears before him and he can't recall who she is. But he thinks he knows her so he asks her to take Rin and Sakura to safety. His only concern now is the evil within the grail. His body is already falling apart and he will die. Shiro knows he has to destroy the thing though, and sees an image in his mind that will let him do it. He summons Saber's sword and cuts through the black thing; dying as he does so.
Later, Sakura wakes up one morning in Shiro's room. It's odd that he's not there, so Sakura gets up to go help in the kitchen and make breakfast. But he's not there. She thinks that's strange and goes to look for him around the house. But he's not there. Once she reaches the shed the realization of what happened hits her and she falls to her knees weeping.
After a time Sakura comes to grips with it all, and in fact it seems like Rin had a more difficult time with things. Sakura sells the Matou household and buys Shiro's house where she found true happiness for a time. With a darkness that had always been in her heart, one would think she would sulk and wallow in self loathing. But Sakura can't do that. All the sacrifices, all the pain, struggle and heartache were for her. He asked her to atone for it all and she will by living a happy life. That's also why they made a promise to each other: to go see cherry blossoms together.
And spring comes. It comes again. And again and again. She knows he'll never return, but she sees the cherry blossoms anyway and waits for him all the same. And finally springtime comes in the twilight of her life. Sakura sits with her sister's granddaughter talking while watching over the blooming trees. And then finally she sees him, young and handsome just as she remembers; in the distance waving.