Prosper is the poster-boy for Treasure decks, and is actually more of an impulse-draw Commander, but its six of one and half a dozen of the other
Summing it up All in all, while Ive seen some angry reactions, the changes arent that big of a deal
I had to look this one up, too, and my assumption was correct: he hails from Innistrad
Pokemon Trading Card Game Japanese (2002) It took a few years and revisions for this design philosophy to seep through to the Japanese version of the game, but once a standard card back was decided upon, it stuck
That means they get to stick around, you double any enter the battlefield triggers, and sometimes you just get a very large and terrifying army very quickly