It definitely wasn't his first try exploring the forts in the base for Xerneas, but after a little bit of searching, he finally came across one with a decently large tree in the back with a deer laying down in the snow in the middle.
She was black and blue with a small bushy tail and beautiful antlers, shimmering in the moonlight with beautiful shades of blue. She also seemed to have something glowing between her hooves, Giratina didn't really pay much attention to it, but he was able to see some kind of long pyramid shaped crystal that sort of looked like a prism. Glowing with multiple pale colors of the rainbow. Once Giratina dashed in, she immediately turned around.
"Gira?" Xerneas exclaimed, looking shocked that he was able to find her. "How did you-"
"We can't talk now, we have to get out of here!" Giratina said in a rush, running over to her. Xerneas got up and went to him, but not before she was able to pick up the crystal she had with her.
Giratina heard the crashing of the Pokémon coming and wasted no time taking Xerneas's hoof and jumping into the black and purple portal he created. Soon enough, he felt himself on snow again and looked up. They were outside of the base, but the Pokémon inside were already coming to get him and Xerneas. Giratina let go of her and immediately started dashing away from the fort, with Xerneas quickly following behind him.