Casting my tie votes for KirbyRider1337's Reuniclus and ToadBrigade's Nidoqueen. Most powerful special Ground attack in the game ftw :)
"It can see the future from the movement of the stars. When it learns its Trainer's life span, it cries in sadness."
Z-Crystal Name: Gothitellium Z
Z-Move Name: Twisting Fate Wheel
Z-Move Type: Psychic
Z-Move Power: 190
Required Move: Future Sight
Z-Move Description: Gothitelle raises its hands and conjures a massive, whirling disc of Psychic energy above its head, similar to a Wheel of Fortune carnival game, with mysterious, white, Unown-like markings on it. A gigantic white laser erupts from the middle, black lightning crackling through it, and whites out the screen as it envelops the opponent completely.
Z-Move Effect: Does damage. At the end of the next turn, the Pokemon occupying the target's current slot is given a Perish Count of 3, as Perish Song.
Now Shadow Tag will NEVER be unbanned! But I guess Gothitelle is at least semi-viable in AG and VGC now? Obviously less useful as a move without STag, but I'd be interested to see if it was viable to run for some reason in NU.
"It grips prey with its pincers until the prey is torn in half. What it can't tear, it tosses far."
Z-Crystal Name: Pinsirium Z
Z-Move Name: Dishonorable Execution
Z-Move Type: Normal
Z-Move Power: -
Required Move: Guillotine
Z-Move Description: Pinsir clamps its claws down on its opponent and slams it on the ground in a frenzied beating, walloping it multiple times before jumping into a spinning suplex and mashing the opponent to the floor headfirst in its death grip.
Z-Move Effect: If Pinsir's current Attack is higher than that of the target, the target faints. Otherwise, this move fails to execute (heh). Ignores Sturdy, Focus Sash, and Protect/similar, but merely breaks Substitute.
The thought process here was "good enough to be equal to Pinsirite and good enough to give up an actual item for." It looks more broken than it is, Ghosts are immune to it making it a complete waste if you misplay (and not safe to use early on) and well...you have to give up a moveslot you were using for coverage on standard Pinsir for the useless Guillotine. However, very very fearsome with Moxie; it makes Pinsir THE ultimate wallbreaker.
"Has a rock-hard hide that is worn like armor. The long horn on its head is sharp and highly venomous."
Z-Crystal Name: Nidokingium Z
Z-Move Name: King's Arsenic Charge
Z-Move Type: Poison
Z-Move Power: 160
Required Move: Drill Run
Z-Move Description: Snorting and stomping the ground, Nidoking's horn begins to glow a dark purple. It lowers its head and rushes at the opponent, earth shaking, slamming the horn into them and thrusting upwards to launch them away as an aura of Poison energy suddenly ripples outward from Nidoking's body.
Z-Move Effect: If this move completes successfully, for the rest of the battle (including switch-outs) ALL Nidoking's attacking moves have an additional 30% chance of
badly poisoning the opponent, working similarly to the effect of Poison Touch. This counts as a "secondary effect" for the purposes of activating Sheer Force and being removed by Sheer Force.
Nidoking can now run physical sets with this! (albeit with limited application). Interesting things that now get the SF boosts: Superpower, Sucker Punch, Megahorn, Power Up Punch, Aqua Tail, Earthquake, Stone Edge. Or you could just spread poison with Beat Up and another ability. Your choice. This move gives it more of a surprise factor but it is still kinda limiting. Basically using a set with this gives up a little bit of Nidoking's consistent power for the ability to have a one time nuke and still deal higher damage output than normal, as well as making its physical coverage stronger. Hone Claws is an option I guess.