This is a very cool and simple idea. Great one for your first suggestion. I imagine this as a light wave that keeps waving at the enemy creatures weakening and confusing them.
However, i think there is no need to remove the multiple one-by-one targeting of this card (but you are the one to make the decision about that). Adding a new mechanic or code is needed most of the time when a new card is implemented.
The reason is that this card kinda fixes it's own flaws by itself. While targeting the second time,if you cancel it, it would be not using this upto it's full potential and the entire chain would end there (if it works the way i think it would).
Balance wise i think the unupped one could use a price drop to 2 light quantas. It's effect only delays for 1 turn.
I think that this kind of multi-targeting along with the way this card is designed, it will be very fun if implemented.