My Shadow Thinks I'm Weak, So It Changed Class to Shadow Monarch Overnight

This is an era dominated by professionals. The poor rely on mutations (god-tier talents), while the rich rely on technology (rare items). With nothing to his name, Zhang Yun plans to lie flat and give up, choosing a healer class so he can coast along until the end. Who knew his shadow would refuse to go along with it? [Your shadow thinks you’re too weak, so it changed classes into a Shadow Monarch overnight!] [Your shadow used the skill “Shadow Gate” to pull you into the “Shadow Realm,” where it began retracing historical events to find suitable heroic souls!] [You have made a pact with a heroic soul and obtained the Shadow Hero Queen of the Full Moon, Rennala (S+)!] [Your shadow killed the dungeon boss “Rock Lizard Wyrmling,” extracted its shadow, and transformed it into a Shadow Soldier. You now have permission to summon “Shadow: Rock Lizard Wyrmling”!] [Your shadow has sent over the dungeon completion rewards...] With his shadow big brother packing up and carrying all the bags, Zhang Yun, the healer, became even more determined to lie flat. Why work hard when you can win without lifting a finger? That is, until... He discovered... The enormous threats hidden in these historical events and in the real world...