Do I have to choose what damage is prevented by Phaedraxa's Auspex Rune?

Name

Do I have to choose what damage is prevented by Phaedraxa's Auspex Rune?

Details

Phaedraxa's Auspex Rune (Activate immediately after a turn order card is drawn: Prevent any damage that the players or Gravehold would suffer during that turn.) prevents all damage dealt to players and/or Gravehold. The 'or' is inclusive.

Cards

Mages

Phaedraxa

Nemeses

Other

Auspex Rune

References

https://boardgamegeek.com/article/25584911#25584911