The article explores the concept of entropy-stabilized oxides, where configurational disorder is engineered into mixed oxide systems by populating a single sublattice with multiple distinct cations. This approach promotes novel and entropy-stabilized forms of crystalline matter, where metal cations are incorporated in new ways. Through rigorous experiments, a thermodynamic model, and a five-component oxide formulation, the authors demonstrate that entropy predominates the thermodynamic landscape and drives a reversible solid-state transformation between a multiphase and single-phase state. In the single-phase state, cation distributions are proven to be random and homogeneous. The findings validate the hypothesis that deliberate configurational disorder provides an orthogonal strategy for discovering new phases of crystalline matter and untapped opportunities for property engineering. The study highlights the potential of entropy-driven transformations in oxide systems, particularly in materials with ionic character, and suggests that similar phenomena may occur in non-metallic systems.The article explores the concept of entropy-stabilized oxides, where configurational disorder is engineered into mixed oxide systems by populating a single sublattice with multiple distinct cations. This approach promotes novel and entropy-stabilized forms of crystalline matter, where metal cations are incorporated in new ways. Through rigorous experiments, a thermodynamic model, and a five-component oxide formulation, the authors demonstrate that entropy predominates the thermodynamic landscape and drives a reversible solid-state transformation between a multiphase and single-phase state. In the single-phase state, cation distributions are proven to be random and homogeneous. The findings validate the hypothesis that deliberate configurational disorder provides an orthogonal strategy for discovering new phases of crystalline matter and untapped opportunities for property engineering. The study highlights the potential of entropy-driven transformations in oxide systems, particularly in materials with ionic character, and suggests that similar phenomena may occur in non-metallic systems.