An Ender Shard is an extremely potent crystalline source of energy, and is a semi-rare gemstone found on The End (or whatever's left of it). It is effectively a piece of hyper-compressed matter. With the power within a full crystal, it has enough potential to power every single electrical or x-powered vehicle or machine within a parsec or two. At the same time. Luckily, they are extremely rare and found shattered into tiny pieces. But even a tiny, millimeter-long fragment can power a massive star cruiser. They are truly disastrous if left in the wrong hands.