Yeah, that was my problem. Taking too much time between playing this means I didn't remember anything about the chain command or pressing up to get to it. One thing I'm still struggling with is keeping the meter full though, i know reviving takes some of it but it just disappears so quickly on me.
Warning an ally during a vision also uses one bar. So you don't really want to do that unless you
need to. And of course it goes down while you're not in battle. And I posted the ways it fills up
a few posts up, which you should find useful.
For Xord, I would recommend fighting the minions, but only to get your party gauge up since you can do it faster on them. Once it's full you can focus on him and use the chain.
Your arts are leveled up, right? That allows them to cooldown faster as well as increase their effectiveness (deal more damage, heal more, better buffs, etc). Sharla shouldn't have any trouble keeping your party members in good shape as long as you're leveling her arts up.
Anyway, here's the Abaasy at level 79/80 video. Sound is pretty terrible since I couldn't really keep a steady framerate while recording. Pretty major spoilers if you're not to Fa
A
, aside from that it should be fine. Details are in the description.
http://bit.ly/L1i6qu
Edit: And special thanks to Starworld_UK for this. That Xenoblade info he linked before was really useful. The trick is actually very simple: Abaasy is so high level that there's no more penalty for fighting him at the level I beat him at than there is fighting him at level 99. It's still important to note that you'll have much lower stats due to the 20 level difference so it's not equally easy, but the actual stat penalties won't be any different.
Edit2: Apparently somebody else has done it at level 80, not surprised. No chains, toppling, or Monado, but they did drag him into a corner so apparently he wouldn't use his arts. I wouldn't consider that much less cheap since they were using DoT and Sharla which basically made it a battle of attrition primarily against his "auto-attacks." Not to say his level 80 kill was unimpressive, any kill around that level is going to require some sort of cheap tactics - be it that or heavy use of topple/chains - given the disadvantages you face.