"In these paintings he is sometimes portrayed while dancing, other times while fighting, playing or hitting someone with a club. It is not clear who the phersu is and what it does but it is believed that from the word phersu, in the sense of "mask", it derives the Latin word "persona", which from its initial meaning ended up indicating a complete human being, a persona."
Check it out the PHERSU project on the website: PHERSU on LVFDS.