Congratz for drawing your own art. It's not an easy job to do at all.
My tips to improve the art would be to make it more flashy. Also trying to make the yellow to more white would fit with the Light theme although i don't have mush idea to do both of that. Just my opinion.
Now on to the card, being a mid cost card for light it does great within a mono light deck but i doubt this card would be useful in any other deck. The first effect of this card which debuffs every non-light creature would pose a problem for the deck maker to include this card in many decks.
This card has two effects tapped into single spell card,
The first part is the one that debuffs every non-light creature by -1|-1. Second one which grants 2 hp per light creature.
The first part is very poorly done imo. Not only does it thematically fit with the theme of light (Light is supposed to exalt their own creatures instead of debuffing others) but would cause problems in duo to rainbow decks.
The second part is a good idea, but there are already too much spells currently in light that heals - From holy light, luciferin to miracle.
Also both the effects does not work together very well in most cases unless one is running a mono light deck. The idea does not seem very innovative or fun.
My final opinion is that this card can be improved a lot more. Currently, it feels a bit like 2 quick random effects tacked into one card which does not work very well. But the cool side is that this card will be awesome for mono light deck lovers.
Removing the first effect of the card and slightly remaking this card is what i would do if i were on your place.
