We describe a class of self-dual dark nonlinear dynamical systems \textit{a priori} allowing their quasi-linearization, whose integrability can be effectively studied by means of a geometrically motivated gradient-holonomic approach. Using this integrability scheme, we study a new self-dual, dark nonlinear dynamical system on a smooth functional manifold, which models the interaction of atmospheric magneto-sonic Alfv\'{e}n plasma waves. We prove that this dynamical system possesses a Lax representation that allows its full direct linearization and compatible Poisson structures. Moreover, we construct an infinite hierarchy of mutually commuting conservation laws for the dynamical system and prove its complete integrability.