Gengar Mime Jr. - SuperWildfire28

3-2-2 Gengar Prime
2 Mr.Mime
2 Mime jr.
2-2 Muk
2-1cinccino
Pokemon Total = 18

2 twins
2 trickery
2 interviewers
2 sage
1ruins of alph
1 lost world
4 pluspower
2 life herb
2 switch
3 energy retrieval
2 poke ball
1 great ball
Trainer/Supporter Total = 24

16 psychic
3 dark
Energy Total = 19

Strategy
This deck focuses on Gengar Prime putting pokemon in the lost zone, then winning by declaring  yourself the winner with the lost world stadium.  While this deck has attacker that can take prizes, it would be more effective to not necessarily rely on them.  Mr. Mime lets you see your opponents hand to see if there are any pokemon in it that can be put into the lost zone with gengars attack.  Mime jr puts the top card of the deck into the lost zone, but the chances of there being a pokemon are slim without something like slowking to stack the deck.  Muk brings up benched pokemon, confuses and poisons them, giving gengar time to work.  Cincinno is a back up attacker that can hit for 100 with a full bench.

Pokemon Analysis
If you're going to run Muk, I would suggest that you go with Mew Prime that can 'see off' Muk, then use the attack as its own.  This will give you the free retreat to get back to gengar easily to attack.   Mew can do the same thing with Gengar, so I'd suggest adding 2-3 Mew Prime to the deck.  If you do this, I'd add in another gengar prime.  I'd add in a 2-2 line of slowking so that you can control what your opponent draws into, potentially slowing them down, as well as stacking the deck so that you can put a pokemon into the lost zone with mime jr.  To make room for these changes I'd drop the cincinno line.

Energy Analysis
I'm not sure why you have dark energy, but it's not needed.  Your pokemon have low energy costs, so you should only need about 8 psychic energy.  Including 2 rescue is an option to reuse your pokemon when they get KO'd.

Trainer/Supporter Analysis
The benefit of Gengar decks is that since they don't rely on taking prizes to win, they can really utilize Twins and N, so I'd max out both of them to 4 each.  You'll need 4 collector to get your bench set up early in the game.  With enough shuffle power, you shouldn't need so much energy search and recovery, so I'd drop the energy retrieval and the interviewers.  More shuffly power means 3-4 PONT, 2 juniper and possibly 2 cheren if you can find the room.  You'll need more than one lost world too, so I'd increase it to 2-3, dropping the ruins of alph.  You'll need 4 seeker to ensure that your opponent has a pokemon in their hand to send off to the lost zone.  You won't be attacking much , so there's no need for plus power.  I'd also drop the trickery, sage, poke ball, great ball and life herb.  3-4 communication is much more reliable than pokeball and great ball for getting the pokemon that you want.  1 super rod will let you reuse your pokemon and energy, just in case you run low throughout the game.

Overall
I've had a few Gengar decks submitted recently which makes me wonder if they're going to be making a comeback. It would be fun to play one at a tournament.  I think once this deck focuses on putting pokemon in the lost zone rather than just taking prizes, it should be much more consistent.