What with both of them being capable of travelling between worlds, these two Mews can get involved in a wide variety of shenanigans, including being adventurers for a bit.
They drastically diminish their psychic powers of course as to not just immediately overpower everything, but going on adventures, whether just the two of them or as a part of a larger party, is something they both enjoy dabbling in.

As for how they do as adventurers? Of the two, Lapis is the only one capable of any sort of direct usage of magic, which combined with her more cautious nature, means she often takes the backlines as a mage with surprisingly capable spellcraft. Usually though, her small size means that her garments tend to have to be rather light as to not hamper the flow of magic in relation to her own body.
Meanwhile, Crystal is a highly competent melee fighter, with speed and dexterity plenty enough to have her able to hold her own in most fights with little issue, topped off by that she can be shockingly stealthy and silent, even without considering the possible drawbacks of being bright pink.

The two do still get in all sorts of silly or devious shenanigans of course, as it just adds to the fun~

Art done by the superb  LexHanley