cr:6.2.2b

If a layer-continuous effect has variable values (such as X), the values of those variables are determined when the continuous effect is generated and do not change thereafter. If the effect is a continuous effect that applies to an object that does not yet exist, the variables are determined when the effect first applies to an object and do not change thereafter.

Example: Tear Limb from Limb has the text “. . . the next Brute attack action card you play this turn gets +X{p}, where X is its base {p},” which is a layer-continuous effect where X is determined at the time the effect first starts to apply to an object, not when it is first generated.