I attack with Borborygmos Enraged. My opponent blocks with a 6/6 (which means Borborygmos will die). When Borborygmos Enraged deals damage to the player, I assume I still reveal the top 3 cards and put lands into my hand as part of the triggered ability. Am I able to use the "Discard a land card" ability with the new cards I draw with the triggered ability or is he dead and I can't use that ability?