The second set of a million minds believe that reality is too fragile to support their existence, so they expect that as they grow stronger, they will fall closer and closer to their origin.
This is why they believe that it is inevitable that they will fuse with their origin. Even if they are wrong, the other set of a million minds believe that they can force the fusion with their origin with brute force and power.
A million minds sounds like a lot, but it is just a drop in the bucket of how many minds Legion has. Only a billion minds might count as something significant for Legion.
But Legion still wanted more. They continued to assimilate everything, ranging from matter to energy, and even dreams and thoughts. They took and took until they couldn't take anymore. Then they fell into their origin.
