I thought everyone knew this thing but I've read some comments so I hope it helps.
Now, both the "good" Tasara and the snake buddy are figuring out what “evil” Tasara is planning. It's like, Tasara's brain is split into two and in order for them to make a move (like take down the fucked up empire together with his shit ass coward king father) they need to observe the evil Tasara. Evil Tasara is the missing piece of the puzzle.
Evil Tasara is there to protect the “good” Tasara from pain and reality. Watch some Multiple Personality Disorder Cases and you'll get what I'm tryna say.
THIS IS WHY I LOVE THIS SHIT SO MUCH.
Oh so its(the evil one) still tasara
All this time i'm guessing that the evil tasara might be the soul or something of the dragon who cursed the family
I remember reading Tasara being so hurt and traumatized because of what Nara did to him (Evil Tasara told Nara himself). His brain couldn't keep up with the situation and created the “evil” Tasara who can remember ALL THE STUFF from Tasara's past, including Nara's betrayal. It's like a defense and protective mechanism of the brain. Tasara created another version of himself to remove the trauma and pain he's been feeling therefore forgetting Nara because he's the reason why he's in pain. It's basically a Multiple Personality Disorder.