Jez has a really good luck that makes things often go in his favor, even in situations where the odds should be against him. Because of this, lucky (I’m guessing that’s short for Luck) breaks with good timing and helpful coincidences happen around him more than normal, sometimes even on a very large scale. It can lower the chances of things going badly and raise the chances of success, but it is not something that works perfectly every time.
But do know this: it does not mean he automatically wins, and it is not the same as him freely controlling destiny whenever or HOWEVER he wants. Jez still needs to fix his own mistakes too sometimes, he’s a small boy. Jez can still be harmed, it’s just more likely he’ll survive or make his opponent slip up badly like missing attacks or eventually making the fight take longer