Movie S6.

Numerical star skyrmion twist for a value of the anisotropy χ04. The S1,2,3 Stokes degree of polarizations are plotted in the left panels over a 60×60μm2 area. Several concentric circles in real space (each represented with a different color) are conformally mapped onto the Poincaré sphere on the right panel (the l-line corresponds to the green color curve). The dynamical twist is similar for each circle, highlighting the generalized skyrmion features. At around 65ps the twist angle has reached 90∘ and the S2 and S3 distributions in real space have roughly swapped with respect to initial time. Upon longer time the twist leads to a complete reversal of the initial star skyrmion into its conjugate state, the lemon skyrmion.