This card can be useful in a Fiend deck that uses "Dark Necrofear", as its effect banishes 3 Fiends for its special summoning. If you use 2 or 3 "Dark Necrofear", this card could be a good beatstick, or a useful tech card for getting all of those banished Fiends back into play.
Use cards like "Axe of Despair" to increase an opponent's monster's to 3000 or higher. Let the monster attack you directly and use "Inferno Tempest" (your Deck must contain at least 20 DARK Attribute monsters). Then Summon "Doomsday Horror".
Use "Chaos End" to destroy all monsters on the field. The effect of "Doomsday Horror" will return all of your DARK monsters to your Graveyard. Now you can Summon powerhouses like "Rainbow Dark Dragon" or "The Dark Creator" to Summon more monsters. Improve this combo with "Chaos End", "The Beginning of the End", etc.
This card works very well with "Necro Gardna", because it allows you to reuse them when it's destroyed and sent to the graveyard. If you opponent activates an effect that destroys spells and trap cards, you can chain "Call of the Haunted" to special summon "Doomsday Horror"; after your opponent's card resolves, your "Doomsday Horror" will be destroyed, and then, just before its effect resolves, activate the effect of the "Necro Gardna" in your graveyard. They will be banished by their own effect, and immediately returned to the graveyard due to the effect of "Doomsday Horror".
This card can be used along with "Necroface" and "The Dark Creator" to slow or prevent decking yourself in a banish or DARK deck.
This card can be used with "Dark Armed Dragon" to reload DARK monsters for "Dark Armed Dragon" to remove from play.
This can can return Djinn of Rituals that were removed from play with their effects to the Graveyard to allow them to be used again for Ritual Summons, as well as other effects.
This card is useful in a "Destiny End Dragoon" Deck, especially if you use it together with "Fusion Gate" and "Chain Material". That way, you can summon three "End Dragoons", and "Doomsday Horror" will have at least 1800 ATK. Also, you can generate a lot of fodder for the revival effect of "Destiny End Dragoon".
This card can help an Infernity Deck for two main reasons. Firstly it can put cards back into the graveyard after you banished them with cards like "Hundred Eyes Dragon", "Phantom of Chaos" and "Infernity Break". Also if your opponent runs cards like "Macro Cosmos" or "Dimensional Fissure", this card will have a lot of ATK because all "Infernity" monsters are DARK attribute, and even if it is destroyed you can then load your monster back into the graveyard where they excel.
Pick this from your Deck by activating "Creeping Darkness" to gain a powered-up monster which resets your graveyard for powerful cards like "The Dark Creator" when it's destroyed.
This card is useful to use in a deck with "Rainbow Dark Dragon", due to it' effect meaning it will have (at least) 2100 attack points from "Rainbow Dark Dragon", and if this card is destroyed the monsters used to summon "Rainbow Dark Dragon" return to the grave, allowing it to potentially be summoned again without needing to destroy more monsters.
This card can be useful in a The Phantom Knights deck, as it can be powered up by the banished The Phantom Knights and when it is destroyed, you can reuse the The Phantom Knight's effects in the graveyard.