If Aegislash uses its "Hard Bashing" attack against an Espathra with "Stance" that evolved last turn, will I damage it or not?
Yes. Hard Bashing gets through all effects, including Stance.
Source: TPCi Rules Team (2023-11-09)

Relevant cards

Note: All applicable cards may not be listed below.
SV4_134
SV4_134
SV4_81
SV4_81