In a medium skillet or saucepan over medium heat, whisk together the buffalo hot sauce, melted butter, and garlic powder until emulsified.
Add the drained white beans to the skillet and toss to coat. Simmer for 5 to 8 minutes until the sauce reduces slightly and the beans are thoroughly heated.
Warm the tortillas using a dry skillet or microwave until pliable.
Distribute the buffalo bean mixture evenly among the eight tortillas.
Top each taco with shredded cabbage, diced celery, blue cheese crumbles, and green onions.
Serve immediately.