Question - Skill: Magical Aptitude

Regarding that new academic skill "Magical Aptitude" ....

‘Magical Aptitude’ – The wizard has a keen aptitude for magic and can push himself beyond the normal limits to produce a storm of spells. He may attempt to cast two spells each turn as long as he is not engaged in combat. However, after resolving the spells make a Toughness test. If he fails, suffer an injury and treat Out of Action results as Stunned. This skill may only be taken by warriors capable of casting spells. Sisters of Sigmar and Warrior-Priests may not use this skill.

If the model has multiple wounds, is this taken as a wound, or does it count as them instantly being stunned regardless?

Answers could depend on where the 'new' skill is found. Where did you encounter this skill?

Pretty sure it's from the 2002 Annual. It should act exactly the same as the Chaos ritual Dark Blood: aka since it specifies an injury roll and not a wound it doesn't matter how many wounds the caster has, they still have to roll for injury.

Not new... it appeared in Town Crier 7, p. 9. Here is how it is worded there:

"Magical Aptitude: This skill may only be taken by a warrior capable of casting spells. It may not be used by Sisters of Sigmar or Warrior Priests. The warrior has a keep aptitude for magic and can push himself beyond normal limits to produce a storm of spells. The warrior may attempt to cast two spells each turn as long as he is not in hand-to-hand combat. After attempting the first spell, he must take a toughness test. If he passes he may attempt a second spell that turn or even cast the same spell twice. If he fails he must roll on the injury table immediately with no saves treating Out Of Action results as Stunned instead."

This version of the skill is very close than Klawful's version, but with one important difference: Klawful's version says the model suffers an injury (which would mean a two-wound model would lose a wound) but the TC7 version specifies that a model who fails the Toughness test immediately rolls on the Injury table, so having multiple wounds would not help. As far as I know, GW never modified this skill and the TC7 version is the correct one. I might well have missed a change, though.

The 2002 Annual reprinted the skill with no change in wording from the TC, which is rare. (See p. 87)

Both the TC and the Annual would be the 'official' version of the skill.