Any hints/tips towards combat? Still fairly early in the game, had trouble with the were-fox girl.
Also, when team comboing, the X shows up, does this signify anything in particular?
X stands for a Cross Hit. It's when you catch an enemy in attack between either your Solo unit (L Button) or Support unit (R Button) and your two main characters. You see the EXP meter on the bottom right? The only way for it to go above 100% is to execute a Cross Hit, otherwise it caps at 100%.
Basic battle strategies I use:
1) Make sure you use each unique attack (A, Left + A, Right +A, etc) once to get the Attack+1, which lets you do one additional attack at the end.
2) Make sure you have 3 units ready to attack a boss in a single turn that have EXP meter at least somewhere near 100% (like 80% to be safe early on). That way, you can unleash your special attack (Y button) after you've dealt the max combo.
3) Make sure you're attacking with both a Solo unit attached and a Support Unit nearby if possible, or at least a Support Unit.
4) The goal is you want to keep the enemy/boss in a cross hit as long as possible. I usually start a battle by immediately summoning the Solo unit and immediately tapping neutral A (or forward A depending on the attack animation) so that you immediately go into a Cross Hit. Wait for the solo units silhouette to appear on the top screen, and when they're moving off screen, that's when I call in my Support Unit. This keeps the enemy/boss in a Cross hit for just about the entire combo.
5) At the end of the combo, unleash your Y button attack.
6) If an enemy has shields, you want to attack normally first without calling your Solo/Support. The trick (for me at least) is to call them in right as their shield breaks, and you catch them in a cross hit. If the enemy's shields will take more than one attack to break, call in your Solo/Support unit a bit earlier to break the shield faster. The goal is to break their shield in one attack and not have to waste your next attack on the shield, increasing your damage potential.
7) Basically, if you break a boss' shield within one attack and go immediately into a cross hit and then keep the cross hit up as long as possible until you can't attack anymore, then you can finish up with a "super" attack and you will do a huge combo (sometimes upwards of 100 hits) and deal around 10-15K damage in the early goings (increases over time). Most early bosses are like 30-40K.
8) If at any point the cross hit stops, and you're back to juggling the enemy, try to time the next attack to land just before the enemy/boss is about to bounce off the ground. You'll deal critical damage. This applies to your Y attack, too. You can deal significantly more damage this way.
9) When you KO an enemy, do not just stop! Keep a combo going on ANY enemy, even one KOed, as long as you can to build up EXP! Especially if you have Solo/Support assists left!
10) Don't bother ever using DEFEND against an enemy attack unless it is a boss or you absolutely need a unit to survive. Always use Counter. You get the 5% EXP bump from their attack + whatever EXP you gain in the counter attack. Plus, you're dealing damage.
11) If you're at 130% or more early on in the game, use FULL DEFEND against boss attacks (if you can, sometimes they do a multi-attack in which case you have to eat the damage). You will most likely be able to gain enough EXP to hit 100% again on your next turn with that unit.
Of course, this is just how I play it. I'm sure there are more advanced strategies and some stuff I've overlooked, and perhaps better tips for the earlier chapters. I would also say look at your Skills by hitting X to bring up your menu and see if one of those might work to your advantage.