A Key Event

Canon
A Key Event is a Grand Legend that when used produces a confluence of circumstances that makes a way to advance: most literally, production of a key. It can be used to forcibly grant a Keyblade immediately, or unlock certain locked things (mostly those that are supposedly unable to be unlocked by other/normal/any means). A Key Event is a member of the Six, a set of Grand Legends. It usually takes the shape of a badge depicting an unlocked padlock, and can be activated by clenching it while thinking of the problem to solve.

Rather than certain victory, it is certain possibility. The key, if functional as a literal key, is almost always produced immediately on site. In some circumstances, especially more metaphorical keys or those requiring faraway action, it will only render it possible, e.g. making it a choice those involved can take. This is more likely to happen if it is an extremely convoluted and potentially unstable 'key figure' such as a variant of the Namesake key, wider circumstances, or the actions of an important political figure. Additionally, being able to use that key depends on the ability of its wielder(s) and circumstances that A Key Event may not necessarily control directly even after several uses.

Otherworlds
It has been claimed similar to Zhuge Liang's Noble Phantasm Chu Shi Biao (Dispatch Troops) as an authority to acquire or be miraculously granted what is needed for a situation in a timely fashion.