Use Labyrinth Builder as early as possible, but only use it if you have any way to remove or negate ritual weapon.
All trap cards in this deck are to help deal with ritual weapon. The Emperor's Holiday would be the best out of all of them since he negates the effects of all equip cards.
Keep stalling with Labyrinth Wall while using draw cards. Only set Crystal Seer if you have at least 2 cards left in your deck, and only use Shard of Greed if you have at least 4 cards left, to avoid clogging your field.
Just like the usual The Unhappy Girl farming decks, attack Mokuba's monsters with it to prevent it from attacking you. You won't be receiving damage upon attacking monsters with higher attack and defense than The Unhappy Girl's attack since you have the Holy Guard Skill.
Unlock a character and have them at the gate is different things. For example, I have unlocked both Pegasus and Paradox Bros long ago during their first event, but just got them available at the gate recently just like everyone else.