Combine the chia seeds, milk, matcha powder, and maple syrup in a bowl and use a whisk to mix thoroughly. Place the bowl in the fridge to allow the chia pudding to thicken.
Make the Purple Smoothie:
Combine the orange juice, water, banana, blueberries, and pineapple in a blender and blend until smooth. Add extra water if needed to facilitate blending.
Assemble the Witch's Brew Smoothie:
Pour a little bit of the purple smoothie into the bottom of a glass, then add a few spoonfuls of the chia pudding around the sides so that you'll see the "bat warts and lizard scales" peek through for serving. Continue layering the smoothie and chia pudding until the glass is full. Top with whipped cream and a sprinkling of extra matcha powder to complete the look.