Destem and deseed the ancho chile, then add it to a small saucepan with 3 cups water. Bring to a boil, reduce heat to low, and cover until the soup is simmering.
Peel and dice the onion. Mince the garlic. Drain and rinse the pinto beans.
Place a large pot over medium-high heat with 2 tsp vegetable oil. Once hot, add the diced onion, minced garlic, cumin, dried oregano, and 1 tsp salt. Cook until the onion is translucent but not browned about 2 to 4 minutes.
Add the pinto beans, crushed tomatoes, and corn to the pot. Stir, lower heat to medium-low, and simmer. Transfer the rehydrated ancho chile (use more or less depending on your affinity for heat) and 2 cups of the cooking water, 1 tsp of salt, and just 1 of the tortillas to a blender. Blend until smooth.
Add the chile tortilla mixture to the pot, cover, and simmer soup over low heat until ready to serve.
Thinly slice the remaining tortillas into 1/4 inch thick strips. Wipe the small saucepan clean and return it to medium-high heat with 2 tbsp vegetable oil.
Fry the tortilla strips until golden brown, about 1 to 2 minutes. Transfer them to a paper towel-lined plate and immediately sprinkle strips with salt.
Halve the avocado. Remove the pit, dice the flesh into 1-inch cubes, and add to a small bowl. Pick the cilantro leaves and add them to the diced avocado along with the juice of half the lime. Gently toss to combine.
Cut remaining lime half into wedges. Divide the tortilla soup between large bowls. Top with fried tortilla strips and diced avocado. Serve with lime wedges.