This is my deck for Kaiba lv 30. It's very cheap since you can get all the UR and SR cards from the Card Trader. I always get 8000+ asessment points playing only 2 glossies and 1 prismatic. I have a 95% win rate with it because you only lose if you draw no monsters or Riryoku Fields in the first 3-4 turns. That's why I choose to use LP Boost α, so I can have extra life in case I have bad draws.
Maybe it's very self-explanatory how to use it but if you have any questions about the deck just let me know.
You don't ever need to attack with Unhappy Girl because there is no D.D. Warrior in lvl 30 Kaiba's deck. So basically you just use it to stall until you can summon Blue-Eyes, Magician of Black Chaos or Twin-Headed Thunder Dragon, at which point you have won the game. Be careful not to summon them before he has used both of his Enemy Controllers or you have enough Riryoku Fields set up though.
Kvda, you just need to summon Unhappy Girl as soon as posible and stall until you can bring your big guys and kill all of his monsters. You play 3 Riryoku Field because the only problem cards are his 2 Enemy Controllers. Once you get rid of them you wait until the last turn to attack directly with your Piranha buffed up by Riryoku and Gift of the Martyr (use them with either of your big monsters).
Unless you can get 8000 assessment points consistently against his lv40 deck, there is no reason to farm lv40 over lv30. And this applies to every single LD duelist. Check this if you don´t believe me: https://www.reddit.com/r/DuelLinks/comments/5xq591/guide_farming_lds_proof_that_level_40_lds_arent/
This is cool... Just when you have 3 cards of Unhappy Girl... Wasted gems for 65packs of Valkyrie and didn't get any one of 6 Unhappy "RARE" card (I got 2 UR and 4 SR from 65pcs)...
I see the consistency of this deck. Bad hand always in 2 condition : for 3-4 turns, you draw : 1. No monster and 2. No riryoku field...
I'll share my 60% win rate of my deck!
I removed 2 blue eyes, 1 riryoku and added serket, beud and 1 shard of greed. Had unhappy girl in almost every starting hand and his twister destroys shard of greed so I could summon serket and beud without problems... but maybe I was just lucky to get unhappy girl in 1st round... still cool alternative deck though
I'm glad it's working for some of you. I've updated it to remove 1 BEWD and add 1 Pot of Benevolence. I tried using 1 Kuriboh instead but I still prefer Pot to avoid having BEWD as my last card (which for some stupid reason happens to me very frequently).
elements unite with paradox is 100% winrate vs lvl 30 kaiba, but I've been farming like 2k white keys and NO SR NO UR, I think they downgrade the drop rate to 0.5% per box, bcs it's stupid, 2k white keys and no SR/UR, bullshit; still 100% winrate tho