Nintendo has shared a trailer for the upcoming Fell Xenologue story in Wave 4 of the Fire Emblem Engage Expansion Pass.

Similar to previous waves, Wave 4 will be available at the start of the next month: more precisely, 5th April 2023.

In addition, Nintendo Japan and the Fire Emblem Japanese Twitter shared additional information.

First, here’s the official artwork for the two new characters, Nel and Nil. Plus their profiles.

Nel (VA: Romi Park) is Nil’s older twin sister, a strong woman who fights alongside her brother. Together with the summoned Alear and Nil, she embarks on a journey to collect the 7 bracelets to save the world.

Nil (VA: Takuya Eguchi) is Nel’s younger twin brother, a kind-hearted young man who assists his sister. He feels ashamed that he’s not as talented as his exceptional older sister.

In the Japanese version, their names are El (Elle?) and Il.

Meanwhile, here they are in battle. We already saw Nel fighting as a dragon in the previous trailer.

Nel and Nil are both described as inheritors of the Fell Dragon’s blood.

Next, a short dialogue scene with Nel and Nil, presumably at the start of the Fell Xenologue.

Both of them currently reside at Lythos Castle. Apparently they’ve been fending off mysterious foes for a long time.

Also, a new section has been added to the Japanese Fire Emblem Engage website, specifically for the Fell Xenologue.

Here’s the story and world summary:

The protagonist was investigating a strange presence at the Somniel when they end up in another world, after following a call for help.
There, they meet the dragon twins Nel and Nil.
Together with the pair, the protagonist embarks on a journey to collect the 7 Bracelets, where the Emblems reside.

The setting is another world with a continent of Elyos that’s similar yet different.
Here, Lumera the Divine Dragon Ruler sealed away the Fell Dragon Sombron by sacrificing her life.
Meanwhile, her successor, the next Divine Dragon (the protagonist) has also perished.
Now there is nobody to unite the world and, with no justice to be found, the world is in a state of cold war, with each country trying to suppress each other.

Some gameplay details.

In the Fell Xenologue, there are various restrictions during battle and battles are slightly tougher than the main game. At the end of a battle, fallen allies will return regardless of Casual or Classic mode.

Allies will enter each map with fixed Level, class and inventory, depending on the map. However, equipped Emblems, support relationships and Bond Rings from the main game will be retained.

Update: Via the European website, you can begin the Fell Xenologue after completing Chapter 6, once you’ve unlocked the ability to transform items at the Ancient Well. Upon visiting the well again, an event will trigger between Alear and Vander, similar to the house leaders’ bracelet. Makes sense given the suspicious nature of the well…

After completing the Fell Xenologue, you can look forward to some bonuses.

Some of the allies you meet in the Fell Xenologue can join you in the main game. You can deploy them, interact with them at the Somniel, view support conversations, etc.

Additionally, you’ll obtain items to unlock 2 new classes–the Enchanter and Mage Cannoneer teased in Waves 3 and 4.

Update: The European website has a bit more info about the item rewards.

Complete the Fell Xenologue storyline to receive the following items as a reward: Mystic Satchel, Mage Cannon, HP Tonic, Strength Tonic, Dexterity Tonic, Speed Tonic, Standard Blast, Magic Blast, Venon Blast, Novice Book, Adapt Book, Expert Book, Master Seal and Second Seal.

Use the Mystic Satchel and Mage Cannon items earned as a completion reward to change a unit’s class, or buy the items from the Item Shop.

The Standard Blast, Magic Blast and Venon (Venom?) Blast weapons are used by the Mage Cannoneer. There are other weapons they can use too. In addition, the Mage Cannoneer’s Let Fly skill depletes their weapon. So presumably you can buy these weapons from the shops.

Lastly, Nintendo Japan added a Topics article with a bit more info.

Here are the profile cards for the Four Wings, the other Elyos’s version of the Found Hounds.

The Four Wings are knights who protect Nel and Nil. Their leader is Zelestia, while Mauvier is the vice-leader.

That’s mostly everything on the official side. From here on is the mini-analysis of the new info.

Firstly, the key art they showed seems to emphasise the dynamic of the Fell twins. Here, Nel is transformed, while Nil isn’t. Also, there’s a glow coming from Nil’s chest, which appears to gather around Nel.

Nil is described as supporting Nel in battle. Also, in his battle video, they showed him fighting with a weapon, without any breath weapons in his inventory.

This is just a guess, but is Nils unable to transform? Is the stone in his chest Nel’s dragonstone or is he, himself, the dragonstone?

What’s peculiar is that in the game files, there are animations for a new lance wielder and axe wielder, likely Nel and Nil. But it seems only the axe wielder has animations to transform, which is the reverse situation. That said, it’s possible Nel is assigned Nil’s animation or perhaps a default animation?

What is more certain are their weapons: Représailles and Revanche. These were new items obtained via the Ancient Well quest added in Wave 3. In the game files, these were labelled as weapons for Nel and Nil.

Potential spoiler. The Revanche axe has a variant for Fell Xenologue 5. Usually, weapon variants only belong to enemies. Plus among the leaked DLC characters, Nil is not listed as playable; instead, there’s a separate prince character called Rafale. Alternatively, Rafale could be Nil’s real name?

Fell Xenologue 1: The Otherworldly Dragon Twins occurs in a ruined version of the Ring Vault in Lythos Castle. It’s likely where they encounter Fogado in the previous trailer. The boss is labelled as ???, so I have a feeling it’s him.

In this map, there are 5 deployment slots–three reserved for Alear, Nel and Nil. Meanwhile you can only bring along 2 more. There will be more slots in other maps.

The defeat condition is the death of Alear, Nel or Nil.

Nel’s Fell Child class has access to A Lance and S Breath. Her personal skill is along the lines of Protector.

You may have noticed the Hard difficulty label next to the chapter name. Although not officially confirmed, the data-mine suggests that you can set the difficulty of the Fell Xenologue independently of your main game.

At the end, it seems you free Tiki from her dark state. Per the data-mine, we knew you fought somebody synced with dark Tiki here–probably Fogado.

Fell Xenologue 2: The Uncanny Flower Castle occurs at Firene Castle, presumably the exterior. You fight Alfred and Céline as bosses here.

This time, there are 8 deployment slots.

Nil’s Fell Child class has access to A Axe only. His personal skill is Complex–I’m guessing a reference to his inferiority complex.

By this point, you also have Zelestia, who’s forced to deploy.

In this other Elyos, you’ll meet familiar characters, but they may not act like you’d expect them to. You probably heard Alcryst downplaying his brother in the trailer.

Here’s a screenshot of Céline from the website, which I’m guessing is from Fell Xenologue 2.

During the battle, Alfred is synced with Hector, while Céline fights without a bracelet. We know from Hector’s Bond conversations that he belonged to Firene in the other Elyos.

Likewise, the data-mine revealed that somebody was synced with Dark Hector.

A neat little detail: the world map for the Fell Xenologue is Elyos but mirrored down the middle. So Firene is located to the west.

I believe Fell Xenologue 3 will occur at the Grand Crossing in Brodia. This is when Diamant threaten to kidnap Nel and Nil. Unlike the main game, you’ll view the battlefield from a 90 degree agree.

At this point, Gregory has joined the team.

Alcryst is fought on this map, although he’s not synced strangely. The data-mine shows that somebody is synced with Dark Veronica. In Veronica’s Bond conversations, she mentions belonging to the other Brodia. Does that mean Diamant is the one who’s synced?

Fell Xenologue 4 should occur somewhere in Elusia. This time, it appears you’ll face both Elusia and Solm’s armies. Interestingly, Solm is a yellow force. So perhaps there will be a three-way battle between Alear’s forces, Elusia and Solm.

This is further cemented by the data-mined indicating Dark Soren and Camilla both appear. Per their bond conversations, they’re owned by Elusia and Solm respectively.

The website also features a small screenshot that’s probably from this map, of Ivy and Timerra confronting Nel?

Madeline and Mauvier both join around this time. Madeline at the least is playable on the map.

Fell Xenologue 5 could occur in Solm, at some ruins. The enemies here mainly seem to be Corrupted. However, Hortensia and Fogado are bosses.

Curiously, Hortensia is synced with Hector, Firene’s Emblem, while Fogado is synced with Veronica, Brodia’s Emblem. So perhaps they snatched them.

According to the data-mine, Dark Chrom is also present. He’s one of the Emblems that presumably belongs to Lythos, perhaps stolen during the raid in Fell Xenologue 1?

On a related note, the data-mined axe-wielding animations for Fogado’s Sentinel class appear to be for him wielding Veronica’s Hliðskjálf. Animation-wise, Hliðskjálf is considered an axe.

Update 2: The Hong Kong version of the trailer briefly shows the map before the Fogado versus Fogado battle. If you stare/zoom in, you may notice something very suspicious.

There’s an axe wielder synced with Dark Chrom, with 2 revival stones. From their appearance, it looks like Nil. This would also fit in with his Revanche axe having a Fell Xenologue 5 variant.

Additionally, one of the Corrupted foes is a Mage Cannoneer. So I imagine you’ll also encounter Enchanter foes, similar to the Divine Paralogues.

The final map, Fell Xenologue 6, I don’t think was shown. This is when you fight the wielders of all 7 Bracelets.

There also seems to be some kind of instant-death map gimmick at play. Where certain zones become highlighted, perhaps to collapse. There’s also some kind of vortex. Plus a beam attack. Sounds a bit like the final chapter, gone crazy!

Major spoilers: I suspect Nil will be the final boss. They seem to have animations for an upgraded class that shares animations with Sombron’s Great Fell Dragon.

Major spoilers, continued: Oh, it absolutely is Nil. In the base game, there are animation calls for multiple special attacks (similar to Sombron’s) during Fell Xenologue 6, with “Il” in the name. At the time, I didn’t know what it meant; my best guess was “Illusion”. But instead it’s referring to Nil.

To finish off, according to the data-mine, Zelestia, Madeline and Gregory should be playable in the main game. They also have S supports.

Fun fact. There is a currently unused function in the base game for calling additional battle conversations for Zephia, Marni and Griss. Presumably when you fight them with Zelestia, Madeline and Gregory. This function is called during every encounter with one of them. I’m unsure how many unique conversations there are though (like maybe you only get a conversation the first time for each?).

We already know Nel is playable, which leaves Nil. I find it strange how they confirmed Nel, but not Nil, plus there’s his Fell Xenologue 5 enemy appearance and possible identity as the final boss, so I have a feeling he’ll be non-playable.

There’s also the question of who Rafale is. According to the dining quotes, Rafale is a prince, just like Nel is a princess. Hmm, could he be this world’s version of Veyle?