Complex sentence: Although never explained in the series, Helena appears to have learned or known information pertaining to DOATEC, most notably the ill-fated'Epsilon project' when she encountered Hayate suffering from amnesia.
Split into simpler sentences: Although never explained in the series Helena appears to have learned or known information pertaining to DOATEC. Most notably the ill-fated'Epsilon project' when she encountered Hayate suffering from amnesia.