This also assumes the Legendary is being named directly in that report, as opposed to it perhaps being a code name like how Necrozma was known as "The Blinding One" or Eternatus as "The Darkest Day" (some places I see the title for the mon vs the event), or Zacian and Zamazenta having nicknames as Sword and Shield.
Granted this is a shorter name than any of those titles, being a single word, but it's one consideration for how "Tera" could be involved by being in its "title" rather than its actual species name.
The researchers named Koraidon as well so I'm guessing they named this thing too. So it's probably meant as an actual name.
Anyway these 3 things keep coming up about it:
-the Tera connection
-The hexagonal shell
-shaped like a disk
Not to mention the implication of relation to imagination or (as the characters see it) time
So there's lots of ways to take it. For all we know it may not even be named after "tera" in particular.
I know Game Freak giveth and Game Freak taketh away and all that, but I'm really wanting to smack whoever's idea it was to remove quick-swapping your party Pokémon's held items, and especially whoever's idea it was to remove the ability to quick-jump through item lists by pressing left/right on the D-Pad. These long item inventories are just the worst.
It also makes going through the pokedex a giant pain in the ass. Doubly so because the sort options don't save your place.
SIDE NOTE
the whole "can't move groups of pokemon into the All Box menu" thing I honestly think is like. A glitch?? Because when you highlight everything the "Search" box disables (as expected) but you can still drag things over the "All Boxes" option it just doesnt do anything. It doesnt even give an error noise telling you you cant do it it just doesnt react at all.
and I was trying to grind up some of the weaker members of the team.
