Like most Magic: The Gathering cards, the value of Llanowar Elves depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Foundations)
If you like manipulating the game and controlling resources, blue, white, and black decks are the way to go
If Festival of Embers is destroyed by a spell, Festivals of Embers will be exiled and then the spell will be put into its owner's graveyard
It may pack less removal power and board presence than either Flametongue Kavu or Skinrender however its lingers round being annoying and costing you tempo far longer than the others
Sacrifice Synergy: Combine token generators that create expendable tokens with cards like "Viscera Seer" that benefit from sacrificing creatures
Assassin's Trophy 10/10 This is just the best two mana removal spell