Where is the scan for Kingdom Hearts 2?

Answer 1

Scan (being able to see the opponents HP) is an ability earned by leveling up. You cannot find it anywhere. In KH2, you get the ability at level 4, regardless of what weapon you choose in "Awakening" (sword, shield or staff).

Answer 2

Well I'm pretty sure that you level up and you get the skill, For specifics i read that you have to get to lvl 4 and then go to ablities and get the scan ability (I'm not usre if it's lvl 4 though :P)