I'm not sure the best way to present that.I like it.
But I like it.
Ideally the latter, Here's what I'm thinking so far.
Cards are basically just letters. For English, we might have h,e,l,l,o is a hand. Obviously these can make a word. Separately they can be played, but you can combine them to make a single more powerful "monster".
So far, it's probably my favorite idea. It's simple enough to not require any kind of language knowledge, but language knowledge is advantageous.
Would you want to have a grammar component or just leave it at vocabulary?