The general paragraph does not really help. As specified in their respective rules, different Lore Attributes take effect at different times. It can be:
- when the spell is being cast by the Wizard (Wildheart, Kindleflame)
- when the spell has been cast succesfully (Lifebloom)
- when the spell is being resolved (Metalshifting, Exorcism, Roiling Skies)
- after the spell has been resolved (Smoke and Mirrors, Life Leeching).
Note that, in the case of Kindleflame, it can even be much later in the same Magic phase (when a spell is being cast by another Wizard), and in the case of Roiling Skies, it can even be in another, much later Magic phase.
The relevant rules have already been quoted above:
BRB p. 498: "After a spell from the Lore of Shadow is successfully cast and resolved, the casting Wizard can choose to immediately swap places with a friendly character of the same troop type anywhere within 18"."
BRB p. 34: "When irresistible force occurs, first resolve the effect of the spell that the Wizard was attempting to cast. As the spell has been cast with irresistible force, the casting player can at least enjoy the effect of his spell before something almost indescribably bad happens to the Wizard and everyone nearby. Once the effect of the spell has been resolved, the Wizard now needs to roll 2D6 on the Miscast table to see what happens to him."
As far as I can tell, the BRb does not specifically state that the Lore Attribute as such is a spell effect, but it is indicated in the description of Roiling skies (BRB p. 497): "When a spell from the Lore of Heavens targets an enemy flying unit or a model with the Fly special rule, the target suffers , D6 Strength 4 hits,
in addition to any other effects caused by the spell" (
Italics mine).
Given that Smoke and Mirrors specifies that "the casting Wizard can choose to
immediately swap places" (
Italics mine), this indicates that it would occur before rolling on the Miscast table.
Of course, if one does not think this is explicit enough, one must then, indeed, refer to the sequencing rule (BRB p. 10): "occasionally you'll find that two or more rules are to be resolved at the same time[...]. Whenever this happens, and the wording is not explicit as to which rule is resolved first, then the player whose turn it is chooses the order" (BRB p. 10). In which case, the result would be the same.