"Chrysothemis" is the 'normal' sister of
Elektra &
Orestes -- in
Aeschylus' trilogy concerning the Fall of the House of Atreus.
I misread your original query which mentioned that another exotic or long name would compete with "
Cassiopeia"; I mistakenly read "complete" - sorry. Although I love Chrysothemis, I much prefer
Delphine as a middle to
Cassiopeia. None will ever forget her lovely name!
Sorry again for my misread!