So the question still remains of wether Defango is Tengri and everything is staged or he says the truth. The first message said "You were one of the candidates. Your intellect is extraordinary." and "You are a truly good person.".
Think about it. What exactly did Defango do to contribute to the decryption of Tengri's messages? Every major step in solving this puzzle was made by someone else. He just reported about it in his videos. In one video he tried to convince people he isn't Tengri and said he does not know how to do "half of that stuff" and he has no idea what all of that is about. Why is he one of the candidates? Why is his intellect "extraordinary"? Do you really thing someone capable of doing puzzle like Tengri's would choose someone like Defango as a candidate and call him extraordinary intelligent?
And by the way. Let's assume Defango IS Tengri, would you post a solution to a part of the puzzle at his position? Probably not, it would just increase the suspicion of you being the creator of the puzzle. The fact that he lied all the time to his viewers about the "spear of destiny" also does not speak for his "big goodness".

My conclusion: it is not unlikely that u/Defango is Tengri137. I would like him to comment on that. I don't want to harass Defango or even harm him, I just try to understand all that.

Anyway, even if he is not Tengri, my trust and respect for Tengri shrinks a bit because I thought they search for someone who is truly intelligent and is able to solve all the puzzles and not someone who just reports about it.