Z-Move Name: Blinding Splash
Z-Crystal Name: Cosmium-Z
Z-Move Type: Normal
Z-Move Power: N/A
Required Move: Splash
Z-Move (In-Game) Description: Cosmog summons rain, creating a puddle. Sacrificing its health, it fills the puddle with a strange dust and throws it at the opponent
Z-Move Effects: Cosmog loses 50% of its health. Blinded by the smog, any moves which can miss will, and the opponent's accuracy will be decreased -2. 20% of confusing the opponent.
Z-Move Name: Solar Eclipse
Z-Crystal Name: Solgalium Z
Z-Move Type: Steel
Z-Move Power: 225
Required Move: Sunsteel Strike
Z-Move (In-Game) Description: Solgaleo roars primally, calling the sun and increasing the power of any move which is used by Solgaleo. During this time, Solgaleo charges up, radiating heat, and then uses the power of the sun to cover the sky with a metallic glance and shoots huge missile-shaped steel beams at the opponent. (If it wasn't obvious, it's a two turn move)
Z-Move Effects: In the charging turn, Solgaleo's Def and SpDef drop by one stage, but hitting it will result in a burn. Any poison moves used will not result in any damage even if not used on a Steel type and will show the message '<Attacking Pokemon's name> poison move was stopped by a metal barrier'.
Z-Move Name: Lunar Penumbra
Z-Crystal Name: Lunalium Z
Z-Move Type: Ghost
Z-Move Power: 225
Required Move: Moongeist Beam
Z-Move (In-Game) Description: Lunala flaps its wings, reflecting light and creating the illusion of a moon in the sky. Lunala then basks in moonlight for a turn as the illusion moon becomes bigger until the moon lights up the sky, and a ghostly essence appears, spirits flooding into the sky and Psychic moves become ineffective and will show this message when a Psychic attack/move used '<Attacking Pokemon's> Psychic attack was dissipated from the spirit's and ghost's aura'. After basking in moonlight for a turn, Lunala flies up to the moon, and sends a beam of moonlight to all the opposing Pokemon and attacks them with big chunks of moonlight.
Z-Move Effects: When this move is in its charging turn, Lunala loses its Psychic typing, becoming purely a ghost type. When the attack is being used, Lunala is in a state in which it cannot be hit by any attacks.
(Did I just write the longest Z-Move description of all time?) :P