I can explain more but it easier if you ask some questions!
In a real Amiibo, there is a NTAG215... we just take a blank one, and clone the data to it, with the right values: Replace the dump UID by the blank NTAG UID, decrypt the dump, calculate the Amiibo password, Write it, encrypt the dump, write lock bytes, etc...
In the PowerSaves/N2, all of this step are made inside the chip of the PowerSaves/N2, so after that you just have to provide Amiibo dumps, select the one you want, and when the PowerSaves/N2 is readed, it will response the right data, calculate on the flag...
Because we don't know what's NFC chips is inside and RC522 can't read all of NFC chips. PN532 have more compatibilities, so maybe it can read the powertag... I've to own one to try to read it!
I see, oddly enough, it seems that Tagmo will read these devices. It looks like this guy already did some work with trying to figure out the way the devices themselves work: http://ghettohaxxx-blog.azurewebsites.net/reversing-powersaves-for-amiibo/
Since Tagmo is open source, we should be able to find the specs for the device within the source.