Okay this is a good question. Two part answer here.
The reason why i use Darkrai is because free retreat is really really good. Laser and Catchers are everywhere, which is the reason why i agree completely with your advice on your addition of Keldeo; However, i had taken Keldeo out of previous builds because i was having Pokemon issues. The only problem that this deck can face is not having a Pokemon on your bench to do 90 on turn 2. Its the absolute worst. Taking out one of the 6 that do 90 on turn 2 is not a solution, what do you propose?
I'm not taking out anything; I'm just replacing some of your offensive options. Keldeo was not only for Special Consition removal, but it also OHKO's Landorus with two Water Energies on it.
The reason why i chose Entei was because he did 90 damage, which was my focal point and also provided stability. When i played a Lando/Darkrai version, as well as others without fire, i ran into the constant problem of not drawing a fire energy, especially if i chose 2 Pokemon that didn't share a blend energy.
Right, but there are other options that hit for 90 as well that hits more of the meta for Weakness. That's the direction I took with my Victini build. The acceleration from the discard is honestly something I overlooked, and I think it's better now that I know it has that, but Terrakion has acceleration from the hand, and it doesn't specify what type, so it's kind of like Trubo Energize for 90 if you have the energy in your hand.
Out of all the games i have played i cannot tell you how many times i have had a Skyla in my hand, and not be able to use it for 1 card, that could change the game. Skyla is the absolute best card in the game. Its the BEST SUPPORTER EVER MADE. I cannot stress how amazing it is to have an automatic ANSWER to anything that happens. I don't have 1 Full Heal or 1 Max Potion, I have 5 of them. That is the only reason why i have any 1 of's in the deck, and ever since i have added those 1 of's, it made all the difference in the world.
Max Potion, I can understand; it can be very handy. But Full Heal is different, especially with Keldeo. It's completely outclassed by other things like Switch and Keldeo.
Enhanced Hammer is great, there is 5 special energy cards in this format, if anything i would add another. Hardly a useless card.
It's not that it's a bad card; it's that it's not priority since it doesn't add to the synergy. I think Enhanced Hammer would fall under tech, and consistency > techs. If you can find room for it, then great.
Ultra Ball - Only time i have ever used Ultra Ball was to get Victini out and up front turn 1 or a Darkrai/Entei on turn 1 for Victini. I dont think anymore Ultra Balls are really needed since after 3 Pokemon i dont need anymore, unless its Bouffalant.
You said it yourself that this deck falls apart if you can't get something on he Bench T1. More Ultra Ball was just to ensure you were able to draw into it or have it not be prized so that you can Skyla into it. I also like maxing out Ultra Ball regardless because it allows you to thin your deck. You Bench the Pokemon you get out and use the Ultra Ball, but you also ditch extra Victini (because you never want to lay down more than one), extra Switch (which you don't need with Keldeo and Darkrai), and stuff you know you won't need. Basically, stuff you might otherwise be N'd into late game and dead draw consequently. That's my reason behind my love of Ultra Ball.
Energy Switch - Entei solves this problem.
Fair enough. I suppose if you keep the Darkrai/Entei exclusive varriant, I don't see any reason for it either except maybe to get the one off of Victini after T1.
When you say i need to be able to grab specific Pokemon to counter threats, i don't think you fully comprehend the concept of the deck. Everything dies in 2 hits, Opponents Weakness does not matter, your Weakness does.
If you took my suggestion in it's entirty, then hitting for Weakness would matter because the deck would be more of a toolbox deck. And the concept of that deck is to OHKO everything over 2HKO'ing everything.You gain a mass amount of advantage, the worst thing you can do is lose that. Playing 2 types of Pokemon solve this problem.
playing 4 Blend and 4 Prism is an absolute must. If you could do anything to ruin your V3 deck that would be it.
I wouldn't say "ruins it" My energy line went 2 Prism, 3 Fire, 4 Grass, 3 Fighting, and 2 Lightning (last minute decided to take out the Keldeo), and I barely missed cut at States. There is a way to do it, but it may be difficult. I started out with 4 Prisms, but that left a lot less room for Basic Energy that could be accelerated from the deck, and I found that I got the T1 Turbo Energizer, but when I searched my deck, the energy I needed was prized. You never want to hinder your ability to turn 1 Victini.....ever.
I approve on less energy. If you use Victini turn 1 and 2, you are set up for awhile and you can draw into enough for another Pokemon.
I don't like N. Not a good card in this format in my opinion, too many card drawing cards. It does nothing but help me majority of the time when the opponent uses it, and when it hurts me i had already lost the game, and it doesn't really matter at that point. N is random, i dont like random or coin flipping.
Then you must be having a blast playing Pokemon 
Also going to note that in terms of what you get off the N, other Supporters are equally random unless you are able to know what you'll top deck. If you don't like N, that's fine, but 10 Supporters with 3 Bicycle is far from consistent. If you dislike it, I still might try one or two since it does have its uses, but I would try to add 4 Supporters (counting Random Receiver) to your list. Maybe 1 Juniper, 1 Ghetsis, 2 Random Receiver?Taking out as much "chance" as possible. This format is also pretty fast.
