In a small saucepan over medium-high heat, combine the agave, habanero and 3/4 cup water and stir until combined. Bring to a simmer and cook for 2 minutes, or until the agave is fully mixed with the water. Turn off the heat and let cool. Strain through a fine-mesh sieve.
In a pitcher, combine the chile-agave simple syrup, lime juice, mango nectar and tequila. Stir to combine. Pour into glasses over ice. Garnish with lime slices.