Tales of Graces F

Can you go back and get that? Cause I missed it. I would be pretty annoyed if you can't get it after that section.

No Mystic Arte can be missed permanently as far as I know. I didn't get that one on my first playthrough until I beat the game =S.

Some more tips
Talk to every cat in the game (one in each city), and you'll unlock the Cat Village. The crazy cat guy's house that Sarah talked about has a dictionary or whatever to let you talk to the cats there. There's a shop and requests available there.

Some difficult to get artes:

You can plant the seeds you've been finding throughout the game at Cheria's house in Lhant. Planting all of them will give Sophie her level 1 Mystic Arte combo activation.

In Zhavert, there's a little sick girl who's collecting dolls. Get her all of the dolls and you'll get Zero Dissolver, Sophie's 3rd Mystic Arte.

Cheria's Virtuous Ray (?) can be obtained by using 4 CC Assault artes 150+ times, finishing 100+ hit combos 3 times as Cheria, or getting to level 100. It's her one spell that does Dragon damage, other than Red Charge Indignation, which the AI can't really do.

Malik's strongest spell, Dragon Slayer (?), can be obtained from Mastering 80 titles, spending 1000000 total Eleth, or getting to level 100.
Malik's strongest burn spell, Blazing Hearts, can be obtained through a sub-event.

 Slight story spoilers

You get it inside the Bathus Citadel very far in (at the end of the dungeon?), at a star marked cutscene after you've gotten the Shuttle working again. You also get a [Drill] item to finish this sub-event in Velanik and start another one somewhere else.

I never got Blazing Hearts in my first playthrough because it was in such an unobvious location that you wouldn't really want to go back to after you were done with it. The other method of obtaining it is getting a total playtime of 100 hours.

Pascal's Fangirl Dream is obtained at Telos Astue.

 Spoiler

In the upper right of 1F, there's a broken humanoid. On the 2F, there should be a star-marked event where you get a Memory Core. You'll be asked to get a bunch of crystals (the ones you use to dualize new weapons with), and they can be really hard to get, since the components are from discovery points and drops, you're not likely to have many spare.
After getting all of it, go to the Humanoid Research Centre 2F (2B? underground), and there should be a scene inside at the upper right (?) involving Sophie, where you get Pascal's title.

The only other way to get this spell is by getting to level 100. This spell has the highest hits per attack of anything in the game that's not a Mystic Arte.