If you summon the warden and provoke it, it still ends up killing you if you have invisibility applied.

Steps to reproduce:
1. Obtain a potion of invisibility.
2. Go to your local ancient city.
3. Trip the shriekers enough times the Warden gets summoned.
4. Become invisible and provoke it.
5. It will manage to kill you.

Expected results:
The Warden would not be able to detect you if you are invisible.
Granted, the Warden is a blind entity. But if you can see through it in spectator and it's intended, surely invisibility does something.