Mexican Bean Soup

Name: Mexican Bean Soup
Ingredients: 2 cans RO-TEL diced tomatoes and green chilies, pureed if desired; 2 cans black beans, drained and rinsed; 2 cans pinto beans, drained and rinsed; 1 can red kidney beans, drained and rinsed; 1 packet taco seasoning OR homemade (see below); 1 32-oz container (box) vegetable stock (or chicken stock for non vegetarian); 1/2 16-oz block Velveeta cheese; shredded cheddar cheese for serving; 1 tbsp chili powder; 1 tsp ground cumin; 1 tsp garlic powder; 1/2 tsp cayenne pepper (or more to taste)