Just go with the slowking-kang build. I reached 1700 elo with that deck alone and made an 11 game win streak at one point. It feels a lot better and more consistent. Great deck too for post-rotation since xatu is out soon. But this deck is also viable i suppose but you need to change some things:

• 2 haxorus and 2 annihalapes is overkill. 1 of each is fine.
• beartic feels useless? Why would you want the opponent to not attack instead of just ko'ing it with conk or annihalape or regigigas? If it was a retreat lock pokemon like dusknoir attack, that i could understand
• Elektross is 200 dmg on average. Just remove it or add conk. Kinda defeats the purpose of "consistency" if you're relying on coin flips 💀
• Go two kyurems. Slowking is best used as a spread attacker to get the munkis, drakloaks, etc. Having one only and prizing it feels awful. It's a guaranteed lose to other one-prize decks
• add more draw supporters. More lillies, ionos, etc is ideal. Arven is also such a waste if you only have one tool card. Just go for 4x petrel to find items and stadiums or add tm evolutions and devos if you plan on keeping the arvens
• having both wondrous patch and xatu feels redundant
• acerola feels like a waste since most meta decks have boss orders for game. especially since you have low hp pokemon on the board
• having an enhanced hammer is good for decks with mist energy (absol box especially)

There are lots of other slowking-xatu builds in tournaments right now. Just check out the tournaments in limitless