The main strategy is the combo with the magic cards "The True Name" and "Card Advance" to search and draw, or Special Summon, "Slifer The Sky Dragon".
The deck is built around the concept of summoning Slifer as quick as possible to blow up the enemy field with "Thunderforce Attack" and/or "Harpie's Feather Duster".
While in the hand, Slifer can be normal summoned easily using many cards that create a lot of tokens, such as "Scapeghost" and "Reactor Slime", or you can Special Summon an "Egyptian God Slime" using Reactor Slime's effects (it represents a triple tribute for a Divine-Beast); "Pot of Greed" (still banned but who cares, this deck is built merely for fun) ensures more draws, more deck speed and therefore more power for Slifer; "Reload" can turn a bad hand into a full combo ready to summon Slifer: the probabilities to draw Card Advance and The True Name at the same time are doubled.
Maxx "C" is the perfect jolly to play against an opponent that relies on Special Summons: discard Maxx "C" while your opponent is Special Summoning and your hand will become fully of extra cards of your deck. This not only increased the possibilieties to draw "The True Name" and/or "Card Advance" but it makes Slifer even more powerfull. The "Yosenju Kama 1-2-3" cards are the Slifer's recharge in ATK: they all return to the hand in End Phase, even if they are in the graveyard.
"Soul Crossing" is here to represent an alternative to "Card Advance" to summon Slifer: soul crossing give an extra normal summon exclusively for a Divine-Beast monster, it's a quick spell card (means that if it's Set, you can active it during the opponent's turn) and, finally, you can sacrifice any number of your opponent's monster for this specific summon. Soul crossing is a jolly that can easily overturn the game.
The field magic card "Mound of the Bound Creator" protect Slifer from being targeted or destroyed by card effects. The trap card "Reckless Greed" is the perfect ambush while Slifer is on the field and an opponent's monster with higher ATK attacks your Divine-Beast: this trap gives to Slifer extra 2000 ATK in a blink, possibly saving the game.
The strategy is all here: the other cards are there for general utility and you can be creative and modify it as you will. I hope you have fun with this deck (besides, this cards aren't too much expensive).