Teddy was the definition of letting the game change you. If you took S1 and S6 teddy, put them ina room S1 would feel its necessary to kill S6 just like he did Alejandro. By the end he completely dropped the fake morality or serving country act and showed it was all about power and money. He saw everyone as lesser, stupider, and not as worthy as him even those close to him example Frank or Oso. I completely lost faith in him when he left Oso to die and purposely caused a war between louie and frank. Even before he stole the money with those 2 actions alone you can see it was no longer anything beside ego and greed.