Deal combat damage to a player or permanent using Living Lore.
Living Lore triggers, causing you to sacrifice it.
When Living Lore dies, its reflexive ability and Nim Deathmantle trigger.
Resolve the Living Lore trigger, causing you to cast Walk the Aeons from exile without paying its mana cost.
Resolve Walk the Aeons, causing you to take an extra turn after this one.
Resolve the Nim Deathmantle trigger, causing you to pay 4 to return Living Lore from your graveyard to the battlefield, and attach Nim Deathmantle to it.
As Living Lore enters the battlefield, choose to exile Walk the Aeons from your graveyard.