Reading every single Sonadow Fanfic (Ao3): 286/4.780
Smut? Strongly implied, but not really
Characters: Sonic the Hedgehog, Shadow the Hedgehog, Rouge the Bat, Miles Tails Prower, Cream the Rabbit, Amy Rose, Knuckles the Echidna, Sally Acorn, Julis-Su other Archie characters
Ships: Sonic/Shadow, Knuckles/Julie-Su (background), Shadow/Infinite (one-sided on Infinites part)
Author Tags: Fluff, Angst, Fear of settling, I promise ill finish eventually, Death, Panic Attacks, mild description of corpses, Stalking, a bit of a slow burn
Author Summary: Life has grown simple and predictable for Sonic and, to be honest, he doesn't completely mind it. The only things that might provide a bit of heartache is his friends' building of their own lives and the absence of Eggman. Sonic tends to be on his own more often, and more time alone means more time to think. Thinking is almost dangerous for him. It makes him slow down and allows all of the past traumatic events that he never emotionally worked through to surface in his head. But still, he tries to keep busy. The routine is comforting at times, but he's definitely not angry when Shadow, whom he hasn't seen in years, abruptly destroys his mundane schedule with a mission that has him feeling young again.
My summary: Sonic and Shadow meet again after a long time, both being long grown up now, and Shadow takes Sonic on his mission after some protest. Sonic realizes Shadow has changed considerably, and they become friends, and more.