or use decks that have many attribute; dark, light, wind, earth for exp: aromage, alien, ... i use aromage is the best bcs u gain life point, the AI has many cards that can att ur life directly
I am using a standard blue eyes deck. You only need power. However, I removed the syncros except for gigantcastle as the AI usually would mess things up. It's not 100% consistent but the ultimate dragons skill helps in case you brick and survive a turn so you can go for the twin dragon (this is done manually as the AI can't trigger skills). The AI can still contact fusion the twin dragon luckily.
This is the shs I've been using. I must say that I swapped after floor 22 to another deck, just to exploit the light weakness. But I've tried against the highest floors and won. No auto duel(ai usually screws up big time)
And this is the deck I autoduel with in the higher floors. If you can get mozarta in opening, you're good to go.
I know the traps are not very f2p, but almost any trap that changes atk or destroys monsters would do it.
If you have more valhallas, get them in there.