Looking over that footage leads me to think that Nana will only powershield when she actually 'turns into' a level 9 computer as other people have suggested. From that and my testing in DEBUG mode today I have some information.



Nana will go through multiple CPU modes - she doesn't stay under the CPU mode NANA all the time.

The CPU mode switch is obviously dependent on the situation, but may also be dependent on Popo/Nana's percentage as others have thought. The CPU modes Nana can switch into are NORMAL*, FREAK, DEFENSIVE, COOPERATE, and STAY. The CPU mode FREAK is when a CPU stays put and attacks opponents if they get close to her. This could explain her not running up to people from time to time and only jabbing them when they get close. The DEFENSIVE CPU mode causes Nana to only use defensive moves such as shields and rolls (I think this is what we see in the video). The COORERATE CPU mode causes Nana to walk around and attack without Smashes. This may be what she does when trying to reconnect to Popo.



Let's say Nana is separated from Popo. The first thing Nana will do is try to find a path back to him. If Nana can not find a path to Popo, she goes into the STAY CPU state (Nana goes into the STAY state and not the NOACT state. NOACT CPUs will not try to recover or DI). If Nana does successfully make it back to Popo, she will enter the NANA CPU state - This is the only CPU state in the game that allows her to perform attacks that the player in her specified port command her to do.



If Nana is separated and the game's code sometimes switchers her CPU mode to NORMAL when Popo or her are at a high percent. When in the CPU mode NORMAL, Nana will start mimicking the moves of a 'normal' computer opponent, reading from whatever level is defined in your port from use of the trick. When either Popo or Nana is at a relatively low percent, The game can switch her to other modes like FREAK or DEFENSIVE as we saw in the video. When Nana is seperated from Popo in the video, she went into the FREAK cpu mode and started jabbing. When she was hit with a laser though, she went into the CPU mode DEFENSIVE.



I encourage you to test this out - Play against a level 9 Ice Climbers and spam projectiles at them (Use a space animal and just laser them). Popo+Nana or Popo alone will powershield a bunch of projectiles, but Nana only will when she is feeling threatened when she is alone. Nana will never powershield lasers when she is following Popo or is in any other cpu mode but NORMAL (When she attacks like every other computer and draws data from a level 9) or DEFENSIVE (when she is using shields or rolls).



*edit: It may have been suspected Nana will go into the CPU mode STRUGGLE (this is when a CPU fights like a normal CPU but is not attracted to fighting humans over other cpus) instead of NORMAL at times, but this is not the case; Nana seems to have a tenancy to target humans when other CPUs are in play.