Warhammer: the Great Crusade Reboots

During the Horus Heresy, a fleet rushing to rescue Terra from Ultramar encountered a traitor ambush during the voyage. After making a huge sacrifice and blindly jumping into the subspace, they seemed to have arrived at a time point ten thousand years later? Thousands of years later, they came to a planet on the dark side of the empire. Everything in this universe challenged the cognition of these veterans. "What does it mean that the Empire was split in two? The Warmaster of Chaos is... Abaddon?! Ah? That pointy-headed First Captain of the Sons of Horus?" "Imperial Regent, Lord Guilliman? The Legion ceases to exist?" In addition, more and more unknown threats are constantly challenging these veterans from thousands of years ago. Enemies of Chaos are attacking everywhere due to the fragmentation of the galaxy. Necrons who have been dormant for a long time are constantly awakening. The Tyranids are devouring planets one after another. The aliens lurking in the dark corners of the city have opened their greedy fangs. Even the Tau Empire is launching another expansion of the sky. PS (The Great Expedition must be carried out no matter what. Ten thousand years ago I took you on the expedition. Ten thousand years later, you will be me. If the empire cannot be as I imagined, then you can take over my mission and continue the unfinished expedition)