A Nasik (= pantriagonal & pandiagonal) 28x28x28 magic cube does not exist. You have to choose for a diagonal ór a pantriagonal 28x28x28 magic cube.
[Composite 1] With a 28x28 magic square consisting of 2x2 proportional 14x14 magic square you can construct a diagonal 28x28x28 magic cube.
[Composite 2'] With reconstruction of a (pan)diagonal 7x7x7 magic cube using the numbers 1 up to 448 in stead of 1 up to 7 in the third grid, you can construct a diagonal 28x28x28 magic cube.
[Composite 1] With a special composite 28x28 magic square you can construct a pantriagonal 28x28x28 magic cube.
[Composite 3&4] Using a pantriagonal 4x4x4 magic cube and a pantriagonal 7x7x7 magic cube, there are three possibilities to construct a 28x28x28 magic cube: pantriagonal (1), pantriagonal (2), and pantriagonal (3)
[Composite 5] Use a pantriagonal 4x4x4 magic cube and a panmagic 7x7 square to construct a 28x28x28 pantriagonal magic cube consisting of 343x proportional pantriagonal 4x4x4 magic cube.