your fanfic version of Ash(final fantasy)and Latias inspired my own series, Pokemon-HALO.
Unbeknownst to the inhabitants of the Pokemon world-Humanity was at war against an alien alliance known as the Covenant bent on wiping out humanity. Hearing that the United Nations Space Corps (UNSC) needed help, Ash-on a break at home from travelling, volunteers to help.
Years later-some species from the Covenant arrive at Alto Mare. Latias and the Latios and the 2 children (a latias and latios) who have taken the title of Guardians of Alto Mare get ready for a fight when Ash returns to the planet....as SPARTAN Super-Soldier Lightning-468.
Deciding that since she wasn't needed at Alto Mare anymore, she would want to travel with Ash, she returns to Pallet Town with Bianca and Lorenzo with the SPARTAN, curious to his identity. When they get to Professor Oak's lab, Ash reveals his identity. Curious to what Ash went through, Latias volunteers to use her Sight Sharing (relying on contact and Ash thinking of the memory) to tell his story.
Ash in the story also has scars, only on his back arms.
How he got them.... arms: "Ash ran along, shooting as he ran, when his energy shields dropped. A Brute fired the spiker he held, two spikes piercing the armor and his lower right arm. Ash screamed in pain, before pulling the needles out of his arm. The brute ran forward and swung his spiker, slashing Ash's left arm just slightly above Ash's wrist."
Back: "A marine carrying a rocket launcher fired at the Brute, killing it. Ash let out a sigh of relief. "Look out!" A marine yelled. Ash leaped forward, and the tips of the two glowing blades of an Energy Sword slashed from his right shoulder to Ash's lower left back. Ash collapsed onto the ground, groaning as the camouflage hiding an Elite dropped."
When Ash arrived, his armor is a steel color with a light-blue details and shoulder pads. His armor was the MJOLNIR Mark 6 SCOUT-variant armor. However in chapter 10, the helmet, kneepads, and left shoulder collapsed. The helmet and shoulder pad was replaced by MJOLNIR Mark 6 COMMANDO armor and the knee pas were replaced by MJONLIR Mark 6 FJ/PARA knee pads. Unlike the first helmet-which had a yellow/orange visor, the COMMANDO helmet has a blue visor.