In a bowl, mix together the chili powder, paprika, cumin, onion powder, and sea salt.

Rub the spice mix over the pork loin and massage the seasonings all over the meat. Refrigerate for at least 1 hour.

Place the pork in a 4- to 6-quart slow cooker and pour in the water around the meat. Cover and cook on LOW for 6 hours or until a meat thermometer inserted in the center registers 145°F.

Alternatively, in a skillet, heat the olive oil over medium heat. Add the pork loin and sear it, turning, to brown it on all sides. Transfer to the slow cooker. Cover and cook on LOW for 6 hours or until a meat thermometer inserted in the center registers 145°F.

Remove the pork from the slow cooker and transfer to a cutting board. With 2 forks or a shredder, shred the pork and set aside.

Arrange the tortillas on a flat surface. Divide the pulled pork evenly among the tortillas and garnish with desired toppings.