Complex sentence: Six Forces send their envoys, doubles of real people; they are "almost" the same as their prototypes: envoy can do only that what prototype can... but unlike them, envoys believe in their own forces, and thus can change the world.
Split into simpler sentences: Six Forces send their envoys, doubles of real people; they are "almost" the same as their prototypes. An envoy can do only that what prototype can, but unlike them, envoys believe in their own forces, and thus can change the world.