Angst

Arthur opened his eyes as the dust began to settle down. He coughed and stood up while grabbing his corroded arm. His mana started expelling the Enders powers from his arms but it was extremely slow. 

A figure was standing across the settling dust cloud with an arm torn away and black matter bleeding out of it. Even though the unique quality of existence gave it more impact on the world, it made it vulnerable to physical attacks. 

"The law of equivalent exchange, to draw out such power you need to make the necessary sacrifices." Arthur smiled from behind his armor. "It's time that you fall here." His body started turning ethereal as he disappeared. 

The creature looked around to find him, but Arthur wasn't there anymore. Whatever traces he left as a person were negated by Lilo's ethereal ability. Befitting of the Elusive Dragon, Lilo could stay hidden for years if no one stumbled upon its lair after being pursued by an Astra-ranker.