It works but not for all units

Probably due to some schema update, I think the mod might now be missing the db/special_ability_phase_attribute_effects_tables to add the Unbreakable effect. Currently the Unwavering trait does not give the Unbreakable effect without the table.

Undead won't crumble unless in combat. Dwarf Long Beards will not route unless in combat.

Im so sorry but how does this come across in battle? Could you give an example?

This is actually nice

Looking forward to trying this in combination with Perfect Stamina Undead for that serious marching skeleton army vibe