Since you don't have the full 60 card list posted here, I can't really tell you what to replace, but I can suggest a build from the ground up.
But before that, from my research, it seems like Hypnotoxic Laser is going to be in Expanded only. I'm only knowledgeable enough to provide you something for Standard which is what the list below will accomodate for.
Pokemon x18
Alolan Muk GX x3
Alolan Muk x1
Alolan Grimer x4
Salandit x2
Salazzle x2
Yveltal x1 (Steam Siege one with Oblivion Wing)
Darkrai GX x2
Tapu Lele GX x3
Supporter x14
Sycamore x4
N x4
Guzma x3
Skyla x2
Brigette x1
Item x16
Ultra Ball x4
Choice Band x3
Float Stone x3
Devolution Spray x3
Field Blower x3
Energy x12
DCE x4
Darkness Energy x8
If I were to be blunt with you, from what I've seen of the Pokemon community so far (online and IRL locals) is that most people are only concerned with meta decks, and things outside of the meta are just "not worth playing." I tend to see a division of "these are the meta people" and "these are the people who play for fun." I don't see many people who do both. That would be my #1 explanation as to why you probably aren't receiving as much help as you're seeing other deck lists get. And by nature, since it's not that meta, people haven't bothered thinking about it since every deck right now is just being compared to Gardevoir GX.
But back on topic,
I dropped the Salazzle line by 1 a piece because you're running 3 Devolution spray to abuse its ability. You only really ever need 1 on the bench. Once you have 1, you spam Devolution spray. You don't want to over stock your bench with free KOs either. You would make sure to search out 1 Salandit when you open with Brigette, so you don't need any more than 2 of those either.
I killed the Guardians Rising Darkrai because you have to expend your turn on attack to inflict only 1 condition, and they might wake up and you lose a turn. I don't like coin flip situations. Not all decks even use their GX attack, and a lot can win without it (Gardevoir GX), so the attack condition is pretty bad. Interesting card but holds no value here.
1 Yveltal for the Oblivion wing to get energy back. It's also your attacker that can attack through Alolan Ninetales' Luminous Barrier. Devolution spray a Salazzle, Drop it for 30 status damage, then swing for 100 for "OHKO."
Kept the same amount of Darkrai GX as a back up attacker and for the GX attack. Getting 2 just so it's much easier to see him during a game than 1 copy.
If you can afford the Leles, 3 Tapu Lele GX for your supporters. If you can't afford it, replace it with 3 Nest Ball. That way you can still drop your Darkrai GX, Yveltal, and basics on the bench and start getting set up.
I opted for 3 Field Blower because you NEED abilities in this deck. Darkrai GX is shut off, statuses are shut off, everything is shut off. You have very few solutions to Garbotoxin shutting off your strategy, so go 3.
3 Float Stone/3 Choice Band so you can get undesired Pokemon out of the active (Salandit, Yveltal, Lele if you run her), and help you hit your numbers better.
I'd very much consider this to be a skeleton build still. Take it and see what you like and don't like about it, and go from there. Any deck I've ever built, including something as meta as Gardevoir GX, is probably on it's 6th or 7th revision in just 3-4 weeks.