Found this game on Salvation and thought it looked fun so I thought I'd bring it here Wasn't sure if it should go here or the custom cards section so if I chose wrong tell me and I'll move it.
I'll go with Delver of Secrets just to see what you come up with.
Ok Pretty Simple Rules
Take a common card, a good common and make that card into a rare.
Try to keep the original card included with making the Rare card.
First Example.
Naturalize
Great Crumble
Instant
Destroy two target artifacts or two target enchantments.
I'll go with Delver of Secrets just to see what you come up with.