I used to write long essays giving advice to composers wanting to compose opera. One sentence was "Your job is to make the singers sound good." I sort of gave up because it became apparent that no one was listening. None of the singers in Thomas Adès' The Tempest sound good at all.
Review previous essays:
Advice to Composers
It's a good subject for an opera but very painful to listen to. This is based on a DVD from House of Opera from the ROH production. I would describe the style as neo-second Viennese school, but entirely without Berg's lyricism.
I will repeat my most basic advice here: If you never go to the opera and don't really like singing, do not repeat DO NOT write an opera.