Combine wine, orange slices, cloves, cinnamon sticks, star anise, and sweetener in a large non-reactive pot.

Heat over medium heat until the liquid reaches a gentle simmer, ensuring it does not boil to prevent alcohol evaporation.

Reduce heat to low and maintain a bare simmer for 20 minutes to allow spice infusion.

Remove from heat and stir in the brandy.

Strain the mixture through a fine-mesh sieve into heat-proof mugs.

Garnish with additional cinnamon sticks or orange slices and serve immediately.