Any Wraithguard unit with a model within 6" of a Spiritseer does not have to test for Wraithsight, just as if a Warlock was accompanying the unit.
A model wearing rune armour has a 4+ invulnerable saving throw. If the move is mounted on a jetbike it may take either the normal 3+ armour saving throw or a 4+ rune armour invulnerable save.
4
3
1
10
4+