Bless effect when casting spells?

[Soyweiser]

No, you do not bless troops by casting other spells. Only blessing spells can bless your troops. And only sacred troops get the blessed morale bonus.

Note:
While it is possible to mod spells that also bless your troops, in vanilla these spells are not there as far as I know.

[JonBrave]

Thank you.

What about what has to happen exactly for my Death bless bonus thingie to affect the target? Whether it's an attack (including arrows?) from a blessed troop, or from a spell from a blessed mage, does it have to cause damage, or get past defense or protection or what for it to affect?