The hardest exam to beat is 140, you can overcome it at less than 70k power only with the well renown lineup that can't be achieved by paying. Seems weird, indeed.

that's true, Itachi the top 3 in ranking currently in 137 which he find it difficult, are they cheating or something?

ninja exam complete in 42 days,

If the guy was 80k at that time is possible, but seems so weird.

Power is good enough. Initiative matter more than power ....power is half of the story.

he's a legend if he has that power in a month

With the right team you could pass it with a little more than 60k BP. I know I did (but also it was back when MB's Iaido wasn't nerfed). So those guys aren't cheating imo.

Also, is Itachi in 140 NE still not immune to debuffs or did they patch him? If they have patched him then I could understand why it seems incredible.

he is immune to debuffs, owns infinite initiative and lands two standard attacks.

i retried the exam today for fun, and if i don't move in the correct way i still lose at 107k power (with common meta teams, not with dedicated team, of course) XD

It is possible, though it requires a good amount of power, ninja, and initiative. Mainly power and Ninja. I'm only now getting to the last few at 70k, mainly because I've been ignoring it.