Ah, yes. Right in the middle of the map, the entrance to Ghido's cave is still there.
With the occasional exception made for Dark Aspics, Ghido's Cave is almost entirely populated by Metamorphs, which shift form, cast their new form's signature attack, and switch back. There are two important things about Metamorphs.
The first is that their Enchanted Fan form casts Aeroga, making it the first chance blue mages have of picking that up.
The second is that, if slain in their default form, they sometimes drop a Staff of Light. The Staff of Light is a step up from other staves available to white mages, and casts Holy when used as an item. Many single-character or single-job challenge runs stay here and farm out these things to make their lives much easier in the long run.
The textbox says "poke poke" but it looks more like Bartz is spinning the turtle around on its shell. Whatever he's doing, it's needlessly antagonizing.
Galuf: Bartz! Stop that!
Bartz: But it's fun! Poke, poke, poke...
Galuf: Sage, I'm so sorry. Please forgive my brainless companion.
Bartz: Wait -- this turtle...
Lenna: ...is the sage?
Faris: By the briny beard of Neptune!
Galuf: And you finally catch a clue! Tarnation, I can't take you anywhere!
Ghido: It's all right, it's all right, no lasting damage... Physically, anyhow.
Bartz: Oh, man, I'm awfully sorry...
Ghido: You should be, boy, picking on defenseless turtles... However, we have more important things to discuss.
Bartz: You mean Exdeath?
Ghido: So, you aren't as slow as you look. What the warlock seeks is within the Great Forest of Moore.
Bartz: The Forest of Moore?
I like Sage Ghido, mostly because when Bartz does that Japanese-RPG-protagonist thing of repeating back the key words in whatever he was just told, Ghido makes fun of him. He'd have a blast in the Metal Gear series, where half of Snake's dialog is repeating what he was just told with a question mark at the end. Alas, he's stuck where he is, never to reappear again after this game.
Ghido: Five hundred years ago, the concentration of evil turned it into a dark creature with a life of its own. That creature is Exdeath. I maintained the seal on Exdeath for five hundred years... However, thirty years ago, the seal was broken.
And despite the villain of this story being... well, a giant evil
tree, I like the backstory for Exdeath too. It implies that inside that Golbez-style platemail he wears is just a swirling miasma of spirits too nasty to kill or banish, so they had to be sealed away until they developed a hivemind and broke out.
Ghido: Yes. Don't interrupt. Dorgann and the others fought hard... Finally, they were able to seal the warlock with the crystals. However, somehow, he escaped.
Bartz: That was our fault...
Ghido: Aren't we feeling self-important, taking all the blame, hmm? Had I meant it was your fault, I would've said that. Seals are meant to be broken. It only means that this time, Exdeath must be destroyed!
Bartz: Where is he!?
Ghido: As I said, the Forest of Moore... Something -- exactly what I do not know, so don't ask -- rests sealed within the forest that he wishes to claim.
Bartz: The Forest of Moore...
Galuf: And Xezat's revenge!
Faris: We'll defeat Exdeath!
Lenna: Let's do it!
Ghido: The Forest of Moore is sentient. It does not take kindly to intruders, and will attack all who attempt to enter.
Bartz: ...
Ghido: Take this with you.
Ghido gives us a branch from one of the trees in Moore and sends us on our way.