If my Beast Energy {*} gets discarded while my opponent has Dusknoir's "Spectral Breach" Ability in effect, does it still go to the Lost Zone?
Yes, Spectral Breach does not affect the Prism Star Rule.
Source: TPCi Rules Team (2020-11-12)

Relevant cards

Note: All applicable cards may not be listed below.
SWSH4_71
SWSH4_71
SM6_117