RSS Post Block

I would like a block that works exactly like the Post Grid block, except instead of getting data from WP_Query I'd like to be able to supply an RSS feed and get the data from there. I have a network of sites, and I'd like to render content from each of them on a portal. It would be easiest to simply supply the RSS feed of my remote site and have the Post Grid block grab the data, store it in a transient (I think WP's RSS fetcher does this already) and render the content exactly like the Post grid.