Glen Elendra's Answer is a mythic Instant card from Lorwyn Eclipsed (ECL), collector number 306. Current market price: $2.23 (foil $3.56), TCGplayer market prices via Scryfall.
This spell can't be countered. Counter all spells your opponents control and all abilities your opponents control. Create a 1/1 blue and black Faerie creature token with flying for each spell and ability countered this way.