  Cu$_4$ triplet clusters form the relevant spin entity for the formation of
long-range magnetic order in the cluster magnet Cu$_2$OSeO$_3$. Using
time-resolved Raman spectroscopy, we probed photoinduced spin and lattice
dynamics in this Mott insulator. Multiple ps-decade spin-lattice relaxation
dynamics is observed, evidencing a separation of the order parameter dynamics
into disordering of long-range and internal spin cluster order. Our study
exemplifies the double order parameter dynamics of generalized molecular
crystals of charge, spin, and orbital nature.
