Out of Focus: Conversely, Ashe and Basch are nowhere to be seen until near the end, where they unexpectedly join your party.
Ba'Gamnan was also a relatively minor villain in the first game. In this game, he plays a bigger role, and even unexpectedly becomes a Guest Star Party Member.
Apathetic Citizens: The Aegyl on board the Galbana when the Sky Saloon is opened. The Sky Pirates who joined fall under this, too. They get better after Chapter 8-2. They don't try to help, though. It turns out they souls have been feed off of. Several Aegyl go unexpectly revenge driven when emotions they never felt suddenly overwhelms them.
Artificial Stupidity: Don't expect your allies to show initiative, move forward with everyone else, or use their abilities with any intelligence. Don't expect Squishy Wizard/White Mage Penelo to take the initiative on healing when you're actually in combat or avoid charging into melee. Do expect her to just stand there staring into space when you try to withdraw her from melee, rather than running as quickly as possible, then watching the boss fight become unwinnable because your healer died.
Ax Crazy: A lot of the Aegyl become this after Velis releases their anima.
No Hero Discount: Tomaj creates the Sky Saloon on the Galbana around a third of the way through the game; it is justified, however - the weapons/material shops are the only way he has to make money, which he uses to buy more weapons and materials.
And even then, he's taking a loss. Chatting with one of the NPCs in the Sky Saloon reveals this, and that evidently the stuff he's selling/you're making would make the people at Draklor Labratory jealous.
One-Winged Angel: It wouldn't be a Final Fantasy game without the final boss pulling one of these.
Required Party Member: You are forced to use certain characters in the missions in which they obtain their Quickenings. Also sometimes done for story purposes, occasionally.
Respawning Enemies: Happens frequently. In missions such as the fight against Zalera, the enemies spawn faster then they can be killed with a normal level party. They could be seen as useful for level grinding, but the amount of experience each battle gives is fixed and can't be increased by killing enemies, instad making maps that are quick to complete better for that purpose.
Side Quest: There are as many optional missions form Tomaj's board as there are in-game missions. They tend to be quite a bit harder, but give much better rewards and the optional Espers. Doing them is required to keep up with the escalating levels of the enemies.
Stripperiffic: Unlike the original game, Penelo's outfit is now one, followed with Fran and Ashe as usual. Averted with Filo.
Summon Magic: A fundamental part of the game; all of your minions have to be summoned, and you can forge pacts with the high-level Espers by completing optional missions.
The Very Definitely Final Dungeon: If a gigantic temple floating in outer space doesn't give you that impression, few other things will. Bonus points for being the first view of space in an Ivalice series game and having a kickass view to the planet below.
Took a Level in Badass: Vaan, who even gets a god blade forged from Odin's soul and goes a few rounds one on one with Ivalice's (arguably) most powerful being. He loses, but still, you got to give him points for trying.
Vapor Wear: Penelo, whose new outfit does not seem to involve underwear at all.