Start by making the simply syrup. Combine the 1 cup of sugar with 2 cups of water and heat in a sauce pan over medium heat, whisking until the sugar dissolves. Remove from heat and set aside to cool.
Juice the lemons to obtain 1 cup of fresh lemon juice. Puree the dragon fruit until it's no longer in chunks.
Mix the cooled simple syrup, lemon juice, dragon fruit, and additional 6 cups of water in a large pitcher.
Notes
This lemonade can be stored in the fridge in a covered container for up to 5 days.