When exactly do you get the benefits from Aid from Lesser Spirits?

The new power card enters play as soon as the Blight card is flipped and the Spirits choose who gets which Minor Power.

You gain the elements on it immediately, and can use it for thresholds that same turn. You can also use the Power that turn, although if it is a Fast power and the Blight card flipped after the Fast phase you will not be able to use it this turn, unless something lets you use a Fast power as a Slow power.