My honest opinion is this, buy more cards and then we'll talk, but If I had to make a deck edit on a theme deck is just an introductory on deck structure and adding more consistency.
Now the thing about most theme decks is in a majority of theme decks only 1-2 cards are actually used in most if not all teir decks, this being said it's not good to get to wrapped up into whats in the deck, it's better to add other things in for consistency, the number 1 thing to think about is draw and re-shuffle cards, these cards add dynamic use into being able to setup your deck ASAP, a majority of these cards as of current are supporter based cards such as juniper, sycamore, N, Shauna, colress, Bianca, cheren, tierno, skyla, bicycle, roller skates, ghetsis, etc. Having a combination of them at a max of 13-14 per deck allows you to always have something to either draw into energy, pokemon and options, the best possible combo currently for the best amount of synergy is 4 N/4 juniper X7 additional supporters. Now to pokemon lines, theme decks like to give lots of basics so you have lots of pokemon, truth is you'll only ever going to need a tenth of that amount per deck unless mentioned other wise, rely on pokemon search cards instead of pokemon, but have your choice pokemon you wish to use at a high amount so it increase's your chances of play ability for instance you want to play darkrai and use darkrai as your main attacker however sableye is a good tech for getting cards from the discard back into my hand so I should have 3-4 darkrai so I always have 1 to draw into at the start of the game and 2-3 sableye so I have this guy at various points of the game. So to pokemon search cards, which is mainly balls, level ball, ultra ball, plasma ball, it's possibly better to play anywhere between 4-5 or 6-7 pokemon search cards depending on type of deck evo or basics +evo techs. Then finally energy, the amount of energy played in a deck should be indicitive of the amount of energy used for your attacker, lets say you use pokemon that use 1-2 energy per attack you can get away with playing 8-10 energy with 2-3 professor's letters so you have the energy that doesn't take away from your pokemon lines and at the same time doesn't take away from your engine that helps everything to come together that much more faster, if you have pokemon that uses 2+ more energy per attack then that's where you'll need anywhere from 12-15 energy per deck regardless of professor's letters. I hope this works to get your deck going in the right direction, just with the basic info here, good luck with it and I hopefully it turns out as a cool experiment for you, peace.
