Place black beans, onion, cilantro, garlic, soy sauce, salt, pepper, panko, and aquafaba into the Vitamix container in the order listed and secure the lid. Select Variable 8. Pulse 8 to 10 times, using the tamper to press the ingredients into the blades. For a smooth textured burger blend on the highest speed for 20-30 seconds. Remove from container and place in a bowl. Let stand 15 to 20 minutes. Divide mixture into 8 patties. Arrange patties onto a baking sheet coated with nonstick spray. Bake at 425°F (220°C) for 8 to 10 minutes. Flip over and bake an additional 6 minutes. For Sriracha aioli, mix the Sriracha, mayonnaise and lime juice together. Assemble burgers on buns with arugula and Sriracha mayo.