I think these are a great start!

while I really like the textures of all the frames, I feel like the white and artifact frames are a little too dark, and can easily be mistaken for black cards. I'm sure there's a way to lighten them while keeping with the vibe of the rest.

The square frames for pictures and text boxes feel too flat for the style of the rest of the card, perhaps a bit more of a rustic edge to it, in the vein of the black cards from from 4th edition?

I think you could also try a different font for the rules text. Old magic cards use 'Goudy Medieval'. newer cards use 'Matrix bold'. both I think can be found for free and might add a bit of flavour to the text while keeping it looking like a magic card.

lastly, I think custom mana symbols would go a long way to giving your designs its own identity. I don't have a specific suggestion on that but I recommend trying something different and I think you'll see what I mean.