Philia - Personality
Describing Philia's personality to someone who's familiar with RPGs in general would cause a lot of frustration, simply because of the archetypical trappings that her roles hold. If you tell people that she's a priestess, people automatically think that she's a timid, wishy-washy kind person who's a healer. Well, two out of three ain't bad (as Philia does not heal; that's Rutee's job), but it also ignores the rest of her personality, which bring an archetypical priestess is only a small fraction of.
If you told someone that Philia was the resident attack mage, they'd automatically believe her to be a nerd with no life, maybe somebody cocky, and could only wield rods and staves, they'd be wrong again (although one out of three ain't bad; Philia is by no means cocky, and she actually wields Clemente, a Swordian... a sword. The biggest Swordian in the game incidentally). It's pretty awesome how she can make her own bombs, necessitating them being named after her.
If you told somebody that Philia had green hair and big glasses, they'd most likely be rushing off to Google or 4chan trying to find anime porn of her. I don't even want to touch that one with a ten foot pole.
Philia is a lot of things, and if there's one thing that Tales of Destiny did right in its first incarnation, it's the production of the character of Philia Felice. Philia doesn't fit into just one character archetype, nor is she a Mary Sue for putting so many different character traits together.
First off, yes, she is a priestess. She is dedicated to her faith in Atamoni and makes sure that everybody knows it by making sure nobody desecrates anything in his name. She also holds a very high bar for modesty; in the manga, she is very anxious about sharing a bath with Rutee. However, she also has a very law-driven or legalistic nature, expecting nothing but the most in moral and ethical uprightness of herself and everybody around her; she even goes as far as trying to evangelize to one of the bosses before the boss fight! That's pretty hardcore.
It is also true that she's smart; much like Estelle from Vesperia, Philia has spent all of her life locked up someplace, and there isn't much else to do but study the outside world through books. As a result, this works gameplay-wise because Philia possess abilities to scan enemy units as well as create her own bombs. Given that she has intelligence, it's only natural that we come to our next point.
Yes, intelligence usually denotes somebody who dabbles in the magical "artes" rather than the physical ones, and Philia sort of fulfills this role. Sort of? Technically, it's not her who uses magic, but Clemente, the Swordian who chose her as his master who gives her magic. It's also not like her studies were what granted her magic, either.
She is very polite, using honorifics for most everybody, even close friends. However, this doesn't mean that she's devoid of emotion; in the final dungeon as interpreted by the manga, Philia had to come to terms with herself when her reflection brought to light two things in her heart; she loved Stahn and wished to be with him, continuing her journey so that she could be by his side... and also despising Rutee and how she has captured Stahn's heart. However, she is able to defeat the shadow of herself by realizing that even if she knows that her feelings for Stahn will never be reciprocated, she knows both Stahn and Rutee are good people, and if being together makes them happy, she is happy as their friend.
Though I haven't played Tales of Destiny 2, it is known that after the battle, Philia returns to Straylize Temple and eventually becomes the High Priestess there. Her devotion to everything she holds dear is evident, as she also was one to remember to meet everything once again once a year has passed.