During early levels of play, it is as simple as summoning monsters with high ATK. Yami Yugi's Power of Dark skill helps boosts all Fiend and Spellcaster type monsters, this will give you an advantage when going against opponents who are not using those types of monsters. Some monsters of those types already good base ATK, this is further boosted from the field spell and the other spell cards in the deck.
Even works in Auto Duel
AI can easily understand how the deck simply works, equipping spell cards to Dark monsters and attacking with them to beat the cpu using auto duel. This is easily doable when you are going against lower level standard duelists.
LIGHT monster, Tribute summon, Trap
Summoning LIGHT monsters, high level monsters and using Trap cards often are recommended since you have to perform them a number of times to unlock some of the Legendary Duelists.
No Wind or Earth attribute monsters to use “Element” monsters effect?
There are currently only a few wind/earth that are either spellcaster or fiend that have good attack, so they won't get the benefit of the field spell but some can be a good choice once you have obtained better cards in the future such as Blue Dragon Summoner or Arsenal Summoner and equip spells that can be used on all elements.
Other useful cards
Although example deck just contains cards very easy to get, you can add/substitute more powerful/versatile cards once you get them. Here is a list of useful cards.
this deck is ok for low level or people who don't have much cards to play with at their current situation.
this is my setup though and open for adjustments/critics as well :)
Field card > Yami
Monster cards > 12
1x Dark Magician Girl
2x Dark Magician
3x Dark Effigy
2x Rogue Doll
1x Elemental Doom (going to switch out as soon as I get another Rogue Doll)
1x Legion The Fiend Jester
1x Emissary of the Afterlife (switching out for Legion ASAP)
1x Arsenal Summoner (switching our for Legion ASAP)
Magic cards > 5
1x Black pendant
2x Thousand Knives
1x Sword of Deep-Seated