Yeah, doing the Sylph cave first did the trick. Leviathan wasn't that tough when the Deluge only killed three people, but basically impossible when it killed four.
Going through the sealed Cave now, and just wanted to comment on some interested things on the remake.
1) Normally I can finish the game well under 8 hours, and it's taking me a lot longer. Part of that is the difficulty, but I think a much larger component is the 3d graphics. Spell animations are absolutely tedious, particularly since they animate one at a time on group spells. Just a much slower game in general. Also the spell animations are ugly. Once again, sprites rule all. Can't wait for DQ4.
2) They COMPLETELY ruined a lot of the balance in this game. The timing between attacks is just retarded now. Attacking is enormously overpower compared to spells, since the chanting time is so low. Also, Black magic does not properly progress with characters. For example, Rydia's Bio was her main stable in the originals, able to do a lot of damage, and it was cast exceptionally fast. Now it's basically useless. Because her main attack spells take so long they are also close to useless in all cases except bosses with counterattacks.
3) Edge is absurdly overpowered for this portion of the game. They limited him in the original by making shurikens extremely rare. Now they are cheap and plentiful, and Edge is insane. Apparently they balanced this out by nerfing the hell out of Flood/Blitz, which also sucks, since Blitz/Mist was such a useful combo for so much of the game.
4) Obviously the designers realized this. The Defender treasure-fight in the original was a really tough group of 5 that you couldn't encounter randomly. Now it's just a regular random encounter. Had it been the original fight, it would have been near impossible because they'd kill almost the entire team before a single call go off.
5) I actually kinda like at Cecil learns Raise now, I always thought that they cut off his White Magic too early, and could give him some more without making him a full White Mage. Seems like they found the right balance here. Not sure what I think about Edge learning more Ninja attacks. Tremor would be cool if it wasn't a Nerfed piece of trash like everything else he learns.
Time to walk into betrayal #2. FU, Kain.