Lemon curd: Bring 2 inches of water to a simmer in a large saucepan.
In a mixer fitted with a whisk attachment, whisk the eggs and sugar together until very light yellow and fluffy. Whisk in the lemon juice and lemon zest. Rest the mixing bowl in the saucepan, with the bowl's base above the simmering water (pour out some of the water if necessary). Cook, whisking occasionally, until the mixture is thickened and custardy, about 15 minutes. Remove the bowl from the heat and stir in the butter. Let cool, cover, and refrigerate until cold. Fold in the whipped cream.
Phyllo triangles: Preheat the oven to 375 degrees F. Line a large sheet pan with parchment paper.
Place 1 sheet of phyllo on the pan and brush with melted butter. Sprinkle evenly with 2 tablespoons of sugar, then place another sheet of phyllo on top. Brush with melted butter, sprinkle with sugar, lay another sheet of phyllo on top, brush with melted butter, and sprinkle with sugar.
With a small sharp knife, cut the stacked phyllo into rows, then cut the rows into triangles, making about 36 triangles. Cover with parchment paper. To keep the phyllo from buckling during baking, place a pan on top of the parchment paper that is slightly smaller to weight it down. Bake until the phyllo is golden brown, about 10 to 12 minutes. Let cool between the pans.
To assemble the dessert, place a spoonful of the lightened lemon curd on 8 plates or place it in a bowl in the center of a serving platter. Stick 3 to 4 phyllo triangles in the curd decoratively or just place them in a ring around the bowl of lemon curd.