Simorgh is an archetype of DARK and WIND Winged Beast monsters with a focus on Normal Summoning Winged Beast monsters and countering the opponent's use of Spells and Traps. It debuted in Structure Deck: Lord of the Storm, but did not receive its first support until Rising Rampage.
Both "Simorgh, Bird of Divinity" and "Simorgh, Bird of Ancestry" are characters in Yu-Gi-Oh! 5D's World Championship 2009: Stardust Accelerator, and "Dark Simorgh" appears in World Championship 2009, in World Championship 2010, in World Championship 2011, and in Duel Arena.
The name "Simorgh" comes from the bird of legend known as Simurgh, a benevolent deity from Persian mythology. "Elborz, the Sacred Lands of Simorgh" is named after Alborz, a mountain range in northern Iran.
"Simorgh" cards focus heavily on Normal Summoning, Tribute Summoning, and removal of your opponent's Spell/Trap Cards. All low-Level "Simorgh" monsters have an effect that activates only when Normal Summoned, either getting cards out of the Deck or, in the case of "Simorgh, Bird of Beginning", giving you another Normal Summon. When combined with "Elborz", which also grants an extra Normal Summon, a "Simorgh" Deck can feasibly Normal Summon three times in one turn. Both "Elborz" and "Simorgh, Bird of Ancestry" reduce the number of Tributes of their monsters (Winged Beast or WIND, respectively) to single-Tribute, making the Summoning of their stronger monsters far easier, especially as every low-Level "Simorgh" can Special Summon themselves from the Graveyard if the opponent controls no Spells or Traps.
Once the high-Level "Simorgh" monsters are finally on the field, their goal from there is to wreak havoc on the opponent's Spell and Trap Cards. "Simorgh Repulsion" in particular immediately wipes their backrow clean for the cost of a single Winged Beast discard (which, as mentioned, the low-Levels can then capitalize on by immediately reviving themselves). Most high-Level "Simorgh" cards also have an effect that discourages the opponent's use of Spells/Traps, either via negation or further card removal, while the original "Simorgh, Bird of Divinity" preys on their lack of a backrow after all is said and done.