When Percy is sent on a quest after the Second Titan War(Or Giant War if it gives you more options) to investigate the lack of monster activity in a small town called Silent Hill over the last 70 years and finds more than even he expected. Guys running around in Gas masks? Creature's that look like they belong in the underworld/tartaurus? Slenderman wearing a odd helmet dragging around a giant kitchen knife? On arrival he meets Dark Alessa and to say the least she's not exactly happy to see him, after sending a crazy triangle helmet wearing dude after him. After learning her past he know he was sent here by the fates for a reason, he promises to always keep her safe while helping her deal with the fanactics that burned her. Alessa then becomes complete and takes the young form of dark alessa except not as pale. But now there is nothing left for her now in this forgotten nightmare town what will she do?
The plot is teaching and raising her to forget her painful past and look to her future with percy by her side outside of silent hill in the world of demigods.
Percy can either adopt her as his younger sister OR her either a daughter. (Depending if you want this to take place after the Titan or Giant War is up to you.)
Not exactly Evil but grey percy vengeful and protective suffering from the affects from Tartarus
Recovering but still Semi dark Alessa still has her Original powers and hydrokinesis. Healing Vegenful and Very protective