Maybe a scenario where the S/O sacrifices themselves so the assassin's don't get caught and they're scheduled for execution?
A/N: I turned these into short scenarios instead I hope that’s okay!
Altaïr You sat quietly in your jail cell, back against the rough stone. All around you were the cries and screams of people who were trapped in the same position you were. Men, women, even some children, all holed up like animals. Sighing you nudged a pebble with your foot, humming quietly to yourself as a guard walked up to your cell.
“Ready to die?” He sneered at you.
“You stood up and casually brushed the dirt off your clothing as you smiled at the man. “Not today, bastard.”
The guard growled and was about to reach in to hit you but stopped short. He let out a pained groan before falling lifeless to the floor, revealing Altaïr in his place, wiping the guard’s blood off his hidden blade. You smiled cheekily at him, “Took you long enough.”
Ezio: You were making the slow walk towards the gallows, escorted by a rather imposing executioner, clad in black and mask on his face. Calm composure remained on your face as you took slow, confident steps. When you stood on the platform you could hear the crowd booing some even attempting to throw things at you, but you dodged it easily enough.
Your eyes scanned the crowd where they came to rest at a group of courtesans and mercenaries idling near the back of the crowd. You were good friends with them and without their help on some missions they wouldn’t have been successful. Some looked on hopelessly, while some courtesans had their faces buried in the shoulder of some mercenaries, unable to watch what was about to unfold.
You gave them a smile as you felt the rope go around your neck, the scratchy fabric irritating your skin. You took a deep breath and closed your eyes. An arrow whizzed by your head, almost grazing you as it embedded itself deep within the executioner’s eye socket, causing him to cry out in pain before another hit him in the heart, killing him. This was followed by sounds of fighting and civilians screaming as they ran away from the battle. Finally you felt a presence behind you before hearing, “Fancy meeting you here.” In a rich baritone. You smiled as Ezio easily cut the rope off your neck.
Connor: You stood on the platform, fidgeting slightly as you felt the guard place the noose around your neck. ‘Where is he?’ You looked out at the crowd for any sigh of him but found none.
“And now, you will die for your crimes.” A voice rang out.
“Wai-” you were cut off as a lever was pulled and the floor fell out from under you. You hung from the rope and began to choke, tears welling up in your eyes. But suddenly you felt the rope go slack and you fell to your knees, coughing and gasping for breath. You stood up, rubbing your neck as you found the knife that was used to cut the rope, lodged in the ground. Yanking it free you came out from under the platform and took in your surroundings. Your eyes landed on Connor, who was currently fighting off a large amount of guards.
You sprinted towards him and joined in on the battle, “Took your sweet time didn’t you?”
Edward: You were being practically dragged to the gallows by the guards. You had been badly beaten before being brought up for execution. Despite the pain the wracked your body you still managed to plaster a smirk on your face. Tilting your head upwards you saw a hooded figure disappear unnoticed around a corner and laughed to yourself.
One of the guards was annoyed by it and stuck you across the face, causing you to fall forward and land on your hands and knees, scraping them. They pulled you up to your feet and asked, “Not so funny now, is it?” You smiled and spit blood into his eyes and raised your bound arms, feeling the rusted chains crack and break as they were shot from a distance. Unable to keep yourself upright any longer you fell to your knees and fought blacking out.
Edward leaped down and killed a guard, before fighting off the rest. Once everyone was dead he bent down and picked you up bridal style. “Are you okay?”
“I’m alive, that’s what matters.”
Arno: You watched quietly as the blade of the guillotine came down and lobbed off yet another head of a criminal. Your breath hitched in your throat at the sight, you’d never get used to seeing it. The prisoner in front of you was yanked up to be beheaded and from the corner of your eye you saw movement in the crowd.
You could see him, Arno. He was running through the crowd as fast as he could, cutting down anyone that dared get in between you and him. Even from here you could tell, by how he fought off his enemies, that he was out for blood. You could make out three other figures and smiled widely. Arno hadn’t come alone, he came with other assassins, close friends of yours.
As the three of them fought of the remaining guards you saw Arno come up to you smirking, cutting off your bonds.
“My hero.” You drawled.