So, I've got Rhen/Lars/Galahad/Te'ijal in my party, all at Level 56, with Bone/Studded/Jeweled/Bone shields, Enchanted/Enchanted/Golden/Enchanted helmets, and Skeleton Armor/Starlight Cloak/Dragon Mail/Skeleton Armor respectively, Fire Amulets all around sans Te'ijal w/ Sould Pendant.

Every time I try to take on the Demon Cave, as the level guide indicates I should be able to, I get completely slaughtered because the imps can hit any character in my party for over a thousand damage, killing them instantly.

Am I missing some sort of armor store somewhere?

Did you buy new armor and weapons at Veldt? There's a store in one of the tents there. Also make sure you get new amulets - I think the girl who sells them (in one of the tent stores) hides in a corner in the back and is very hard to see.

Just because the guide states it's possible at level 56, doesn't mean it's easy at that level. I think I needed to be closer to the low 60s to be able to survive there, comfortably.

The best weapons/armor/accessories you can get at that point are in Veldt.

Ah, okay. I did get new equipment at Veldt. I think I'm just gonna have to level grind a bit. :3

Here's some tips.
I was level 53 going in with best armor and weapons.
I always have Dameon in the party, use Silence Exora to stop them from using magic. Why?
With the best armor, I get no damage with pysical attacks from monsters but dramatic damage with their magic.
Bring plenty of healing items and things will go smoothly.

I reccomend Elini in your party instead of Galahad, since she's a much stronger fighter and she can summon demons.

I did warn that the Demon Caves were a particularly difficult place in my guide

If you find your party is getting hit too hard, you probably need to add in some defense because it looks like your party is mostly focused on offense. Switch out Galahad and put in Dameon (if he's not properly leveled up, level him up as he learns lots of useful spells) and don't forget to equip him with the best armour/weapons. I know some people never used Dameon in the game and got through it fine, but I found he was extremely useful; my party throughout most of the game was Rhen (balanced warrior)/Lars (offensive magic)/Dameon (defense)/Te'ijal (melee fighter).

If you have the best armour and defend against melee attacks with Dameon, you can dampen melee attacks. Use Rhen's Time Twist attack initially to put the monsters to sleep and/or silence them with Dameon so that they don't use their worst magic attacks on you. But, since they mostly use fire magic, your fire amulets should help if they attack you with magic, anyway.

i was about tha level when i explore the cave . did you learn witch dance in sedona? it is very usefull, lower the attack and defense of the imps.(if you succeed in cursing them of course). or just use chicken curse hex ( you can buy it in new witchood, this thing stiil usefull even in ahriman castle!)

I'm at the caves now. Rhen's at level 60. Galahad (whom I've rarely used since I got him) is at level 57, and everyone else's at level 53. I went to Veldt and upgraded their weapons and armors. However, those imps strike each of my characters down in one blow. I've heard about this Pirate John, and I thing I know where he is. I'm going to leave the area for now and get this Pirate John. Should I be doing anything else different? For the record, Lars has yet to join a guild. I'm aiming at having him join the Time guild.

For the demon caves, you really should level up more. I'd have everyone at least in the 60s before attempting it.

Rats. Looks like I can't get the Pirate until later in the game.

Yes, you can't get Pirate John until after you defeat the daeva on the Southern Isle.

Pirate John doesn't have any special skills anyway. He's got a pretty good melee attack, but that's it.