Only 'ardha manav' can achive mani.

One very good statement told by Astika to Shank. Only ardha manav can achive 'mani' not others, not nag (and not manav as well). And it can not be seperated from the special one.

Exactly...and soon the Mahabharat Adhaya is going to start.

And what I found the difference between Mahabharat and Nagarjun is one Arjun found Krishna and another found Mani. This is very noticeable to me. And in Mahabharat nobody from kaurava tried to use or take advantage from Krishna but in Nagarjuna all hierarchy of Nagloka are after Mani. This is quite remarkable. It seems Kauravs have evolved and became scientific in 21st century.

So Maharaj Takshak want to imprison the soul of Arjun in order to destroy his manav part and what remains is nag. And it will be very easy for them to manipulate nag with mani. But I doubt it, what about his software that is base on positive emotion. Sooner or later that will takeover and fightback against the state of predatory nag.

Finally Ardha manav have achieved 'Mani' but with very high price.

As I have said many times, there is still software in his giant head that is base on positive emotion. When he is cool, something can activate that software. But for now he is very passive and his head is under control of designer the Takshak. In short it is SOFTWARE VS HARDWARE that is malfunction.