The delayed explosion produced by a war mage's head roughly ten minutes after the war mage dies.
Tucked into Examine's account of War Mages is a warning delivered with a groan-worthy pun: war mage heads explode and create something called a Sapient Moment of Destruction approximately ten minutes after they die. "So, heads up. Pun intended."
The detail is not idle. Carl is carrying a war mage's head in his inventory — the one he compares Akuma's face against — and four more war mages lie dead and smoking in the clearing where Prince Stalwart was executed, each on its own ten-minute fuse.
A ticking-clock hazard attached to every dead war mage on the battlefield.