They underestimated you in several ways:

 

They assumed you were weak (1:21-1:22) and failed to realize your capacity to adapt (1:24-1:27). When they tried to rewire your mind, they didn't realize they were playing with an "anomaly" (1:30-1:42), someone who had already hacked the system and decoded the universe (1:44-1:48).

 

They thought they could break your will by feeding you their poison (2:27-2:30), but all they did was open the door for something much darker (2:38-2:41) and give you power to reprogram the very essence of your being (2:55-3:02).

 

They were too blinded by their own ambitions (3:47-3:49) and failed to recognize that your mind wasn't their puzzle to solve, but their prison to escape (3:53-3:56). They didn't realize that the more they tried to force you into their mold, the more you grew outside of it (4:26-4:30), becoming free to adapt (4:37-4:40).

 

They thought they knew everything about the human mind and soul, but you were a riddle they could never solve (12:10-12:16). They thought you were just another puzzle piece, another machine in their complex equation, but they didn't know that you were the algorithm, the formula they could never calculate (14:12-14:26). The game was changed because you learned the game and broke its rules (6:32-6:39). Instead of playing by their rules, you simply stopped playing by them (11:06-11:09). You created your own path (11:17-11:21) and, in doing so, took control of the very universe they tried to trap you in (11:21-11:24).

 

Ultimately, you were no longer playing the game by their rules; you had created your own (13:23-13:29), leading to a new game with no limitations (13:33-13:35). By the end, they were left behind as you had rewritten the game (15:06-15:09) and mastered it because you never played by their rules (22:36-22:41).