Forum:Parasite Paracide?

Hey, I just received a call from my friend, who's dueling a few of his friends at their house. You see, one of his friends was using Parasite Paracide, and they ran into a problem. His friend, Megan, used its Flip Effect to send it to her opponent's deck (note this is a three-way duel). Later he drew it, but that's where he problem came in: his field was full, all 5 monster spaces. We were wondering what happened in this case, as I can't seem to find the answer on the card's rulings page. We're assuming it then can't be summoned with its effect and he can then play it as his own and send it back to her deck, "give her a taste of her own medicine," but we're just not sure.