Pour the orange juice and cranberry juice into a large mixing bowl, creating a bright, tangy base with vibrant color.
Add the blackberry syrup or black food coloring to the mixture, stirring gently to incorporate. This will deepen the color and give the punch an eerie, dark appearance.
Slowly pour in the lemon-lime soda, stirring gently to combine without losing too much fizz. This adds a bubbly, slightly thickened texture to the punch.
Allow the bubbling mixture to sit for a few minutes until it becomes slightly frothy and visually swirling, resembling a bubbling potion.
Just before serving, sprinkle a pinch of edible glitter over the top, watching it shimmer and catch the light for a spooky effect.
Use a ladle to carefully pour the punch into glasses or a decorative pitcher, ready for spooky sipping at your Halloween gathering.