Mix paprika, salt, onion powder, garlic powder, cayenne pepper, white pepper, black pepper, thyme, and oregano together in a small bowl.

Heat a large cast iron skillet over high heat until extremely hot, about 10 minutes.

Dip fish fillets into melted butter and sprinkle each fillet generously with seasoning mixture.

Place fish fillets in the hot skillet and pour 1 tablespoon of butter over each fillet. Cook until coating on the underside of fillet turns black, 3 to 5 minutes. Turn fillets over and pour another tablespoon of butter over each fillet; cook until fish flakes easily with a fork, about 2 minutes more.