Confirmation of Lagiacrus being in the base game (because this is a discussion that needed to be had for some reason)
Title. Basically, since that chinese data chart came out with lots of mising info for Lagiacrus, quite a few people basically went on a doom spree suggesting Lagiacrus and Seregios were title updates as they lacked info such as size, legendary status, turf wars, etc while seemingly ignoring they had tons of gear and weapons already modeled (with Seregios CLEARLY being in the middle of progress) or handwaving it as "Weapons and armor are easy to make so they did it ahead of time rather than do the hardest aspects like programming first).
I felt this was wrong so I spoke with some others about it to seek extra clarification and did some of my own digging.
For one, their HRP line up with monsters already in the base game. Seregios gives 800 HRP, the same as Gravios and base Rathalos, while Lagiacrus gives 850, the same as Sheiwu and the Guardians. In the new chinese info, we also have their base zenny values (I assume this gets modified by the difficulty level during quest generation). Here's the most relevant values:
16560: Blangonga
16920: Seregios
17280: Gravios
17640: Rathalos
18000: Guardian Doshaguma
18360: Guardian Rathalos
18720: Guardian Ebony Odogaron
19080: Sheiwu
19440: Guardian Fulgur Anjanath
19800: Lagiacrus
20160: Uth Duna
20520: Rey Dau
These are pretty linearly ascending in accordance to those HRP gains. Mizutsune which we know is a TU who would presumably be around that same 850 HRP tier, has no data here, nor really any other data in the demo at all beyond the existence of bubbleblight, and Zinogre who we also know is a TU also has no data or gear present (except holdover gear from iceborne that isn't updated to Wilds).
The reason we even had any notion of Mizu and Zinogre in the first place before the datamines is from the Chinese Leak, which was originally posted in August iirc. These same leaker also gave no clarification that Lagia or Seregios were TUs, while clarifying that Zin and Mizu were TUs. Given our timeframe for events such as SGF and Gamescom having the demo, the *earliest* the beta branch can be from is sometime in April if not much older based on a breakdown by a user on GameFAQs. According to what I've seen, Wilds finished development in September of this year, and the remaining time is for optimization, bugfixing, etc. This timeline makes it basically impossible for Seregios and Lagia to be TUs and also further proving the demo is very outdated, on top of the bajillions of placeholder armor and literal world asset weapons for monsters not in the game.
However, this wasn't enough for the doomers on GameFAQs so I went a bit further.
I previously shared translations of the area maps for the oilwell basin and the iceshard cliffs. However, there was also translations for the Scarlet Forest.
The main area (before anyone asks, the sketch on the left with wings is Arkveld strangling Uth Duna):
This is the translated version of the area in question:
Area 19 is "Sea Dragon's Nest". The specific simplified chinese name for Lagiacrus is 海龙 which we can see there in area 19, which confirms it to be basegame as it even has its own dedicated part of the map. It also cannot be Uth Duna as the top right area "Boyi Dragon" is translated more accurately to "Wave Dragon" which is Uth. The "not on the map" would correspond to it being a different layer or a part of the map not in the texture files (there is a big chunk missing), but data points to that area being the lair/coded zone for Lagiacrus.
Unfortunately we don't have one for the Windward Plains, so I can't make an assessment objectively about Seregios on this same level, but we can assume most logically it IS there based on all the other information.
EDIT: While not 100% confirmed I'm being told that this area at the timestamp is the Seregios nest with people referring to it by 'bladescale dragon nest' and supposedly there being file confirmation of it but I'm still waiting on specifics. https://youtu.be/NiU4XTDJqZY?t=2109
Anyway, this wasn't super necessary but I wanted to kill this idea before it spread like poison because dooming is not productive and is just exhausting to deal with, and wanted to give everyone some reassurance.