That's it! That's what I was telling you about in my earlier posts!

That boss fight is without question, the most difficult thus far. But it's a pretty epic fight. I'll tell you what I had done to beat him if you need some guidance.
- Use Hope! - Sach may be really useful with Haste, Bravery and Faith, but Hope's got Protect! And he is one of the best medics in the game, and a powerful ravager. Can't go wrong.
- Use Fang! - Casting Libra on Raines shows that he's susceptible to Slow. Exploit that heavily by having Fang in your party and making her a Saboteur when possible. Don't forget each debuff spell she casts does damage and builds up the chain meter. That's not to forget that as a Commando she's like Auron on steroids, and as a Sentinel she can easily soak up the damage from Raine's hard hitting combos.
- Paradigms! - You really have to switch paradigms in this battle. Ideally, you want to get in a defensive paradigm when he's in offense and go offensive when in defense. SEN/MED/MED really helps out for when you're in defense, COM/RAV/RAV, COM/RAV/SEN, COM/RAV/MED, COM/SYN/SAB helps out any other time. I'd use COM/SYN/SAB at start of battle and any other time he decides to do Sepharic Ray, which removes all your buffs, all his debuffs and buffs himself and then wail on him. RAV/RAV/RAV can also build up the chain meter quickly when he's in defense mode. Stagger em, switch to COM/RAV/RAV and then hit him hard, that's really the only way you'll land some big damage on him.
- Accessorise! - Raines can cast some really annoying debuff effects, Fog is perhaps the worst as it messes up your ability to cast spells which is a real downer if it hits a Medic when you need it most. So, with Lightning as the party leader, I maxed out the accessory that grants Fog resistance and equipped it onto her and it didn't hit me so much, which helped a lot, as I can then use her Esuna to bring back Hope and have him heal again.
- Summon! - There will come a point in the fight when Raines decides to go insane, and really hit you hard, I came close to dying after Hope and Fang went down and he had all his buff effects. So I summoned Odin. Not only did he deal a decent amount of damage, but Fang and Hope came back into the battle with full health and no debuffs. Very beneficial.
So that's my tips! It is hard, no doubt about it, it took me more than 5 times to do it which is perhaps the most retries I've ever spent on a JRPG storyline boss since the end boss in Persona 3 or the Demon Wall in FFVII! Just keep at it! The reward for beating him at the end is a very useful item you'll definately make use of, so not only is it rewarding in itself to beat that guy, you also get some sweet loot as a result
