Signing into the Top Mecha at the Beginning: I Invaded the Giant Beast

In 2038 AD, giant beasts invaded the earth. Faced with the invasion of giant beasts, humans were unable to fight back. As a last resort, humans could only build huge stone walls. The construction of huge stone walls barely allowed humans to live a stable life. However, the good times did not last long. Two years later, the giant beast broke through the huge stone wall. At this moment, Ling Yun awakened the top mecha sign-in system... "The host, Ling Yun, is verifying his identity, and the verification passed!" "Host! Congratulations on your successful sign-in and obtaining the first-order mecha Doomsday Crisis. Do you want to summon it now?" This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.