The main reason for this type of downwards price spike is people rushing to sell their copies before the price reaches it's lower stabilized price
This deck also contains a few very strange and unique card designs that really make the Necrons stand out
The casting cost on this card is restrictive, but WotC really didnt want this to be a 6-mana card
His ability lets you turn dead cards into combat strength, and this also makes him really hard to block/remove
Equipment has to be cheap to play and cheap to equip in decks that splash them, and Conjurers Mantle is both
Theres also a large token sub-theme: Grist, the Hunger TideGrist, the Hunger Tide Giant AdephageGiant Adephage Formless GenesisFormless Genesis We got some really fun new cards in this deck, especially Shriekwood DevourerShriekwood Devourer and the backup commander Rendmaw, Creaking NestRendmaw, Creaking Nest