Boil chicken, then shred. Preheat oven to 350. Blend soups, ro-tel, and chili powder. Cube velveeta cheese. Add cheese and shredded chicken to mixture. Crush half the bag of Doritos and layer in bottom of 9 x 13 inch pan. Spread chicken mixture on top of layer. Top of with another layer of crushed Doritos. Can add shredded cheese on top. Bake at 350 for 35 - 40 minutes, or until velveeta is melted.