Credit: Wizards of the Coast The Gold Saucer BPhillipYork: Well if you just want to be flipping coins it's a useful way to generate flips, and it's also a mana dump, and also a way to draw presumably with token artifacts, so all in all it's a pretty flexible toolbox card, which I like
The fact that you get to choose what opponents can keep is * chefs kiss *
With cards, people already know the characters to some extent, and they have personal feelings and attachments from playing the games, so you have to make sure there's no disconnect between the pieces and people's expectations
Finally to help maximize Gix's activate ability we use cards like Bubbling Muck to generate more mana and Reliquary Tower so we have more cards in hand to discard
most of these creatures work incredibly well in concert
These creature types have gotten a ton of support from WotC over time