Att'la's Plate Mail

So, I just stumbled upon this, as we were having a small discussion about casting Eye of the Gods upon someone with the magical armour, which we agreed is not possible due to this rule:

Mordheim Rulebook p. 100 wrote:

Rune of Spell Eating: The Hero wearing this armour is immune to all spells.

However, when reading this, I asked myself the question: What about prayers? It doesn't technically say that the wearer is immune to say, Soulfire. So I suppose it actually only applies to spells (hence the Rune of 'Spell' Eating)?

Prayers of Sigmar wrote:

Prayers of Sigmar are not regarded as spells, so any special protection against spells does not affect them.

Att'la's Plate Mail wrote:

Rune of Spell Eating: The Hero wearing this armour is immune to all spells.

Looks pretty black and white to me. The armour only protects against spells and prayers are specifically not regarded as spells. So, nope, no soulfire protection for whoever is wearing the armour.

Sigmar cares not for your heathen runes!

I want so bad to find that armor for my dwarf noble. That is basically my mission in this campagne.