what are mtg showcase cards Reframing How To Think About Magic Card Frames Showcase - MTG Wiki

So if you're high enough leveled for enemies in random encounters to spawn at very high levels, you can go to a map where Ninjas can spawn with Catch on your characters, and then farm as much of these normally very hard-to-obtain weapons as you want as they keep throwing them at your characters (as the AI will never see that you'll just keep catching them and all AI enemies have an infinite supply of their items)

The deck doesnt seem to be a strong contender as of now but these cards all have a high power level and can potentially see play in the future

The printed rules text for Xenograft isn't too lengthy

Then once you amass an army of Elves, use the next ability