The goal of the deck is to summon slifer, however it would be a waste to stop here, the strong engine use in this deck allow you a lot of summon and draw to summon strong monster from your extra deck stop your opponent to play.
There are the steps :
1 - Summon slifer :
The easiest way to summon slifer is to use his signature trap " the revived sky god ", to use it slifer has to be in GY.
To get slifer in the graveyard there is multiple way, the easiest is to use the fiendsmith engine to XYZ summon beatrice to foolish from the deck, in case slifer is in your hand you can discard it with horus engine," knigthmare gryphon " or " Fiendsmith's Tract ", you can even use " Illusion of chaos " to get slifer back in the deck to foolish it afterward;
Slifer is the deck now you have to set the trap, " lilith, lady of lament " can add it from your deck to your hand, there no real combo to summon her, the best way to use her effect is to normal summon her, summon her from your hand or GY with " tank toy " effect or to use " Tour guide from the underworld " to link summon " Muckracker From the underworld " and summon back lilith to use her effect.
Fiendish Rino Warrior allow you to foolish her so you can once again summon her thank to toy tank or muckracker.
This way you have slifer in graveyard and the revived sky god set, you can use it next turn to get 6 cards in hands and a free slifer.
2 - Build your board :
As you can see the deck use 5 engine :
-- Horus --
It allow you to get free discard and a lot of summon to access strong control monsters like griphon or apollousa, it can also give you from 1 to 6 draw at once if your opponent try to destroy your cards while "duamutef, Blessing of Horus" is on your side
This engine alse give strong recover for your second turn where this deck shine
--Fiendsmith--
It is essentially use to summon beatrice to foolish slifer, in case you can't get slifer and set the revived sky god this turn you can also summon the D/D/D XYZ monster to negate summons or you can use this engine to destroy card on the board thank to Fiensmith engraver effect
--Unchained--
Also a one esay one card combo engine that can give you free extenders, foolish and summon back lilith or you can use it to remove monster from your opponent side.
Unchained Sharvana is lvl 6 so he can also be used for XYZ summon beatrice or D/D/D with fiendsmith cards.
--Toy--
Used to get easily 3 monster on your side of the field thank to toy box who can set toy tank and soldier who summons themselves back when they are send to GY, tank toy can then tribute himself to summon lvl 6 or lower monster from your hand or GY.
--Dark Magician--
" Illusion of chaos " can add magician soul's and get any card from your hand in the deck, magician soul's is used to combo with toys and draw 2, this way you got 3 special summon and draw 2
Hope you'll like it.