This is a planned story.
* One pairing: HagiMatsu. Matsuda is in Arknights. There are some crossovers, but they aren't the main focus. The main setting is Arknights.
A Sarkaz named Matsuda found a lost Sankta in a cave, while the Sankta named Hagiwara found a strange ring in that same cave.
When injected with Originium Arts, the strange ring summons someone who looks almost exactly like its user. Let's call them a duplicate for now. However, only Matsuda can use the ring; Hagiwara can't.
Haha, who knew that even you Sankta had developed racial discrimination?
Every duplicate summoned is Matsuda, but each one is different. The previous Matsuda introduced himself as a Jujutsu Sorcerer, the next said he'd just become a wizard, and this Matsuda was a police officer, while that one was an outlaw...
Hagiwara loves spending time with all the different Matsudas. Since Matsuda himself is sick of having to explain the situation to every alternate-world version of himself summoned each time, he decides to send the two of them off together instead
Oh, it's you. Perfect. No need to explain the situation, then. Let's break through this encirclement.
Sure, no problem. But where's Hagi?
Matsuda grabbed the strap and slung the silver-white Guardian Gun over his back. Its glittering form proudly drew attention to itself, making its owner a walking target on the battlefield.
The messenger Matsuda shrugged.
"Right here. Time to go."
*Crossover with Jujutsu Kaisen, Cultist Simulator, Project Moon, Madoka Magica, and various other strange personal-setting AUs. In short, Matsuda comes in many varieties.
Theme: People should look to the future, but they mustn't forget the past.