In a high powder blender like Vitamix, first blend together the banana, berries, almonds and some water/milk. Once it is blended smoothly add the purple kale, torn into small pieces and remaining water/milk as needed. Add in the protein powder too if using. Blend until it's nice, smooth and creamy.
Notes
If using fresh berries, then don't forget to add ice cubes. High power blenders like Vitamix might start cooking the smoothie if the ice part of it is missing. So either the fruits should be frozen or ice cubes should be used.