Sygg, River Cutthroat Lifegain

While playing Dack Fayden my opponent, playing Nicol Bolas God Pharaoh, cast Sygg, River Cutthroat and the next turn after attacking with it gained 66 life. I stole it using Confiscate and the next turn all my creatures were gaining 66 life per hit. The opponent had no supports in play and nothing on my board (Chimil, Tecutlan, Mox Ruby) would have produced that effect.