there are a million 5's in every color that are cool for cube, Sphinx is a fun one and i also like the teferi / lost truths suggestions but like i think one can hardly go wrong skimping on 5's for a single color, there will be more than enough in every cube and most decks
though i love riptidelab and what you guys do here and chris, you especially are a vigilant designer of cards and cubes, i do think that your assessments of power level are often errant, which i'm guessing is due to a lack of practical grounding in competitive and cube MTG. when mogis's was spoilt, there was not a man who did not go apeshit over its power; when mogis's was played in THS limited, there was not a man who wasn't disappointed. i'm not saying it's a bad inclusion, as it has seen a little bit of constructed play, even, but assessing it with the context of ~6 drafts where you played with or against it, or some standard testing where you threw it in a deck or played against your buddy's brew with it, provides a richer context in which to judge the card.
