Before moving on with the story, it couldn't hurt to take a look in another newly-reachable cave near the shallows outside of Mithril Town. Inside are two Minikin on a raised platform covered in unusual rocks.

The EasyType replaces こうせき (ore) with the more accessible きんぞく (metal).

No tails so far, though. Something to keep in mind for later, then.

Cid's workers mentioned the cave by the Tower of Babwil, though. The tower sticks up through the mountains on the island with Eblana Castle, and the shallows nearby do indeed lead to a cave. It just might connect to the upper tower, where the Crystals are supposed to be, so it's certainly worth investigating.

Inside, the cave has numerous hidden passages in the walls. There are a few minor treasures along the way, but more interestingly, the party soon stumbles across a human settlement, complete with shops and an inn!

The EasyType replaces よもや (yomoya) with まさか (masaka), which has a comparable meaning but is far more common.

This young lord sounds important, and that passage sounds useful. Time to investigate!

The cave continues. A soldier lies on the ground not far inside.

The EasyType replaces the exclamation point with trailing ellipses.

The party finds more collapsed soldiers as they advance further.

A side room after a few caverns holds a save point, and hides a passage containing a Blood Sword in a chest guarded by two Steel Golems.

The Blood Lance works especially well against them.

Shortly after the save room, the party finds a caped man confronting Rubicante himself. The music stops.

自分の胸に聞いてみる (literally "try asking your own chest/heart"), which Edge rephrases more rudely here, is an idiom that roughly means, "you know perfectly well what you did, and you ought to feel guilty about it". Rubicante seems genuinely confused about Edge's attitude, though.

They enter combat. Rubicante, wrapped in a cloak, takes a hit from Edge's twin blades and answers back with a weak Fira spell. Edge responds by using Katon, a ninja flame technique, but that just heals him.

Rubicante stops shielding himself and uses Flamestream, a Flame attack stronger than Figa. Edge doesn't stand a chance.

He turns into flame and drifts up the stairs. Edges gets to his feet with difficulty...

...then collapses again. The party decides it's time to intervene.

Everyone turns toward Rydia, and her theme starts playing.

Remember when Cid told her to at least call him おじちゃん (literally "uncle") instead of おじいちゃん (literally "grandpa")? She does! Cid would be pleased. I've kept the literal translations of the family terms here for reference, and because I'm not sure how else to preserve that nuance. Besides, I like the idea of Rydia going around "adopting" new family members. It just feels like something she would do.

Rosa heals him, he gets up, and Cid's theme starts playing (come to think of it, Edge doesn't have his own theme).

Edge is conceptually a front-row fighter with some magic-like abilities for variety, but he tends to be fairly squishy, with low health and defense (his high evasion helps counteract that somewhat, but with the game mechanics the way they are, you need a shield to get the most out of evasion, and he doesn't do shields). Consider backtracking far enough to buy a Boomerang for his right hand so he can fight from the back row at full effectiveness (for whatever reason, only the right-hand weapon's range matters for ambidextrous characters like Edge) and get a bonus against some enemies for Projectile damage.

Additionally, note that Edge can use all of Yang's claws, but unlike Yang, he needs weapon strength to fuel his attack power, and claws don't provide any. They're still useful for giving elemental and racial multipliers, though. Finally, although Edge boasts of inheriting generations of secret ninja skills, the only one he can use so far is Katon, and it's not much stronger against a single target than Fira, though at least it doesn't cost much, either.

Also, "Edge" is officially short for "Edward Geraldine". Considering how that clashes with his personality, it's no wonder he goes by a nickname.

Finally, if you don't mind glitching a little bit, this is a great opportunity to give Rydia a shield. Make sure you don't have any Mithril (Silver) shields in your inventory, then get Edge to steal one, for instance from the Armed Mammal (Armadillo) or Iron Dress (Ironback) found in this very cave, while Rydia's item menu is open. The game forgets to restrict who can use weapons or shields when swapped during battle if the weapon or shield is newly added while the item menu is already open, so she can put it on then even though she can't normally use shields, giving her a substantial evasion boost to help her survive better. The trickiest part of the setup is making sure her turn comes up quickly enough after his; arranging the party so he's a slot ahead of her and hoping for a preemptive attack may be the surest way of getting that to happen. You may also need to visit her equipment screen after battle for her stats to update. Just don't remove the shield, or you won't be able to put it back on without doing the glitch all over again. This works just as well for other characters, so you could also give Rosa a shield if you don't mind giving up bows and keeping her on staves, and for any weapon Edge can steal, so by stealing from the appropriate monsters you can give any character (except Edge himself) oddball weapons like a Lamia's Harp or Healing Staff if you feel like it.

In the DS remake, Edge starts with more of his skills, but can't use Yang's claws, so that takes some options off the table. The combat algorithms have been redone, so I'm hoping his high evasion will do a better job of keeping him healthy. And, of course, the glitch described above is gone, too.

The cave connects to the outside of the tower at the first floor above ground. There's no entrance, though.

That would be a legendary ninja technique to, as the literal translation indicates, pass right through walls. And because he's only able to do it here for plot convenience, Edge promptly forgets about this ability once the scene ends. It's never again mentioned for the rest of the game, much less used.

Edge takes the lead and brings the party through the solid wall and into the tower. It's a one-way trip, though.

Other than the monsters, the tower above ground isn't much different from the tower below ground, though this section is more linear except for a chest down a conspicuous side path that contains an Ogre Killer axe guarded by four Berserk Ogres.

These showed up in a chest in the basement of Eblana Castle, too, though there were only three of them there. Rosa should try to hit them with Minimum to make them harmless, while the fighters can equip blood weapons and the Faerie Claw (Charm) for that juicy anti-giant racial bonus.

Further on are a chest with a better sword for Edge, what looks like the top end of the teleporter Rubicante used to leave the underworld section of the tower, and a room with a save point. Don't miss the 82,000 Gil in a chest to the left of what's an obvious location for a boss fight, either. Cross the bridge toward the obvious boss location, and a regal-looking man and woman appear as the music fades out.

Wait, the Dark World? Wrong game. Or maybe it's just awkward censorship. Probably that second thing.

They attack, looking more monster than human. This king uses Fira and the queen uses Fire, but neither hurts much, and it's the dialog that's interesting here.

That was one of the oddities of NoA's content policy, apparently. You couldn't say "hell", since that was considered a religious reference, but if it was "Hades", that was considered more of a mythological reference, making it acceptable. But "down to the Hades" still smacks of inadequate proofreading.

After a few rounds, they change color and stop attacking, and the music turns sorrowful.

The king dies.

The queen dies. The party does not celebrate as combat ends.

The screen tints red, and Rubicante appears from a flame.

The Elite Four battle music starts as Edge finishes his line.

However, the battle doesn't start immediately. Talk to Rubicante to continue.

Now the battle begins. During the course of combat, Rubicante alternates between wrapping himself in his cloak and not, and absorbs cold-based magic damage when wrapped up. When he emerges from the cloak, that leaves him vulnerable, but it's also a warning that he's about to use Flamestream, easily his strongest attack and potentially a one-hit KO depending on who it hits. He's not heartless, though. Toss a Fire spell (or Katon, or other fire-based magic) at him, and he'll cast Raise on the entire party (however, since it's coming from an enemy, the spell is subject to magic evade, increasing the chance that it may miss). Physical attacks will provoke a multitarget Fira counterattack, but it's not particularly powerful and shouldn't dissuade you from attacking.

Whether this is deliberate or a glitch, Rubicante's severe Ice weakness remains even when he also has Ice absorption, so physical attacks of that type inflict quadruple damage all throughout the battle. It's riskier to try using Ice magic, since it will heal him if it hits at the wrong time.

Curiously, Rubicante has no particular resistance to Flame damage. He's supposed to absorb it, but the changes when he opens or closes his cloak overwrite the previous settings, and so that goes out the window right away. Rydia might be better off sticking to Fira, even though it doesn't take advantage of a weakness.

In the original Japanese version only, Rubicante will also react to all summon magic by casting Blizzara on himself (this takes precedence over casting Raise if Ifrit is summoned). That's free bonus damage when the timing is right, but free healing for him otherwise.

If physically attacked when at sufficiently low health, Rubicante leaves some parting words before combat ends.

He needs to be struck when he has no more than 1,000 HP left to trigger this. Given that fighters with Ice weapons can easily hit for several thousand at a time to blow right by that, and that magic damage can't trigger them at all, these lines are fairly easy to miss.

Regardless, he has a brief speech after combat is over.

He turns to flame and vanishes.

A voice interrupts the scene.

The minister and some soldiers from Eblana rush in.

On the one hand, I can't come up with any way that じい could translate to "chamberlain". On the other, it is important that he's not just an old man.

That's one way to keep Edge's interest. Sure, he beat the guy he blames for what happened to his parents and kingdom, but what about the guy who was giving that guy his orders? Cain is canny enough that I wouldn't doubt he introduced Golubaeser that way entirely on purpose.

They head back the way they came.

Through the nearby door is a large Crystal room, with three Crystals on their stands already visible from the entryway. However, just inside...

Though it's not possible to see much past the entryway without using a walk-through-walls code, the room has eight stands, with Crystals on all but one of them. None of them have event scripts defined, but they're still handled as interactive objects, and as a result, attempting to examine one crashes the game when it tries to execute arbitrary data. There's also a door in the back of the room that leads to a corridor behind it, partially visible from elsewhere on the floor. However, there's no way back into the room from the other side, and although there's another doorway nearby, that one leads nowhere at all and just causes some graphical glitches.

The party drops into a lower floor of the tower.

Sure enough, the teleporter where they fought Lugae earlier is visible on the other side of the nearby wall. The monsters on this side are tougher, though, and on that note, the party may need to heal up—Rubicante gives free healing before combat, but none after it.

As in the upper section, the path here is largely linear. It eventually leads to a conspicuously large room. Inside...

Edge barges on ahead and to the helm.

Fortunately, it seems he does know how to fly this thing. The Falcon lifts off in front of the tower. Unfortunately, it apparently hasn't been reinforced against extreme heat, and can't fly over the magma. With the passage to the surface sealed off, that leaves Dwarf Castle the only plausible destination.