Forum:Covenant with the swamp king question

I've been playing around with a DD deck on dueling network, and I have a question: if I use Covenant with the Swamp King to fuse 2 dd Pendulum Monsters on the field, do they go to the Graveyard or the Extra Deck?Djt08031996 (talk • contribs) 21:17, August 15, 2014 (UTC)