Though I see it as a niche card, its a very interesting niche card to me. I dont quite mind the fact that its equivalent to 40 fire quantum+ fire lance due to the fact that fire lances main use is unloading on the opponent directly, something this combo still cannot do. Also at most this combo will wipe out 6 cards played, something I can live with.
I would see myself "judging" my own ray of lights combined with eclipse quite a bit, so if we are all prepared for this eventuality I am completely behind it. As far as fitting lights theme I personally think it does because previously light doesn't quite have enough uniqueness to it and would like to see it expand. This definitely fits the expanding theme bill.