This clever engine centers around Melira's Keepers, whose built-in static protection prevents counters from ever being placed on it, effectively turning any source of persist into a permanent loop. By sacrificing Melira's Keepers to Carrion Feeder, you trigger the persist granted by Isilu, Carrier of Twilight (the back face of Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight)—yet instead of returning with a debilitating -1/-1 counter, Melira's Keepers bounces back completely clean. This lets you feed the same creature to Carrion Feeder over and over again, rapidly growing its power with infinite +1/+1 counters while generating endless sacrifice, death, and "leaves the battlefield" triggers.