Better Than a Fidget Spinner

... is a butterfly knife.  After release, Shiv practiced first with a blunt trainer, then with a single-edge, before going back to his double-edge.  Despite its reputation for danger -- which comes from people trying to do tricks with it -- a butterfly is actually the safest kind of folding knife to use.  Its construction means that, once you have it open with both handles in hand, the blade cannot collapse to cut you.