Here's how Darkrai's sacrifice goes in The Skarloey Engines' Adventures of Pokémon: The Rise of Darkrai.
[Alice feels something behind her, and turns around and gasps. Darkrai springs up into action and flies directly towards Dialga and Palkia]
Dialga: ROAR!!! [builds up Roar of Time]
Palkia: ROAR!!! [builds up Special Rend]
Darkrai: STOP!!! [he makes protective sphere]
[When Dialga and Palkia fired their attacks, Darkrai blocks it with the sphere he made and it engulfs Dialga and Palkia, and some various objects disappear. Ash, Dawn, Hiccup, Astrid, Toothless, Stormfly, Skarloey, Peter Sam, Duncan, Willy, Mako, Blythe, the pets, and the other Pokémon look up to the scenes, and it zooms into Darkrai]
Darkrai: This garden is EVERYONE'S!!
Duncan: He's buying us some time.
Dawn: The disk! Let's hurry!
Ash: Hey, come on!
[They raced to the top]
Tonio: Darkrai's blocking the explosion's energy, but for how long?
J.J.: I've got a bad feeling about this.
[The others look up to Darkrai, and he is starting to get weak. And it cuts back to Ash, Dawn, and the other Pokémon racing to the top]
[Buneary quickly used an Ice Beam to stop a disappearing. But then explosion tidal waves that Darkrai's holding appear, and it makes part of the tower disappear and Ash almost falls, but Dawn grabs his hand, Piplup grabs her boot, but then a metal pole Ash is holding disappears, and the three of them fall! But Buizel uses Water Gun to shoot them up into the high ground]
Ash: Buizel, thanks a lot!
[Buizel responds back]
Ash: Hey Pikachu, take care of everyone!
[Pikachu and the rest of the Pokémon start racing up, while Ash, Dawn, and Piplup start making there way up. But as they do so, Darkrai starts getting weaker, and the bubble he made shrinking and Dialga and Palkia are freed. But Dawn notices this]
Dawn: Huh? Ash, come back!
[Ash comes to the scene and he gasp]
[Down below, everyone watches in worried. But then Dialga and Palkia fired some of their attack on Darkrai and exploded! Which made everyone gasped in horror, then Darkrai floats up from the steam and he begins disappearing]
Alice: Darkrai, no!
Bertram: He's disappearing.
[Darkrai keeps on disappearing]
Dawn: But how?
[Now, Darkrai is completely gone. And Pikachu and the Pokémon had watched what happen to him as well]
[Down below, everyone looks in horror]
Sharky: (with tears in his eyes) He saved us all.
Russell Ferguson: NOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!!!
[Then a tear streams down on Alice's face]