The entrance to the air-raid shelter seemed to have been forced open, causing it to be twisted and deformed.
Xia Chao tried to move the door with all his might, only to find it incredibly durable. Even with his cultivation of the Dragon Tiger Arhat Power, he couldn't budge it a hair's breadth.
"It should be some form of composite steel," Xia Chao speculated, aware that such materials are rarely found among mankind, except in specialized tools for four or five-star contracted beasts. They are costly due to their scarcity.
Wealthy individuals often used this special steel to make armor and weapons for their contracted beasts.
"It's stronger than you think. The toughest material you've created can withstand attacks from five-star demon beasts, equivalent to Divinity Transformation Stage attacks. This door is stronger than that; only the full power attack of a six-star beast can break it."