This lethal loop relies on the dynamic scaling of Aettir and Priwen, whose base power and toughness are defined by your current life total. By using Disciple of Griselbrand to sacrifice the equipment, you cash in that massive toughness for a surge of life. Enduring Tenacity catches every drop of that lifegain to immediately drain your target opponent for the same amount. Should Enduring Tenacity ever perish in the process, its own recursion ability safely returns it to the battlefield as an enchantment to keep the engine running smoothly.