Novel An Operator Named "Sierra" (Halo AU/Arknights Crossover)

One of the greatest advancements introduced with the Mk. VII series of MJOLNIR Powered Assault Armor was its Splitspace Disinsertion systems. Theoretically, this would allow for the Spartan wearing it to survive sudden Slipspace transition and be able to be safely recovered by UNSC assets. There is just one problem, even with the advanced systems, the Spartan and suit often just straight up vanish into the 11th dimensional realm of Slipstream Space.

Now, the two members of ONI's GROM Team have become victims of this on a mission gone horribly wrong and have been separated from both each other and the UNSC and have to find ways to survive on the chaotic world of Tera.