Kozilek, the Broken Reality

If a double-faced card is manifested, it will be put onto the battlefield face down. While face down, it can't transform. If the front face of the card is a creature card, you can turn it face up by paying its mana cost. If you do, its front face will be up.

If a face-down permanent leaves the battlefield, you must reveal it. You must also reveal all face-down spells and permanents you control if you leave the game or the game end.

Any time you have priority, you may turn a manifested creature face up by revealing that it's a creature card (ignoring any copy effects or type-changing effects that might be applying to it) and paying its mana cost. This is a special action. It doesn't use the stack and can't be responded to.

Kozilek, the Broken Reality's triggered ability will resolve before Kozilek does. If Kozilek is countered or otherwise leaves the stack in response to that triggered ability, the triggered ability will still resolve as normal.

Turning a permanent face up or face down doesn't change whether that permanent is tapped or untapped.

If a targeted player has only one card in hand as Kozilek's triggered ability resolves, they manifest that card.