In regards to lore, are the Tapu legendaries? Rotomdex refers

Yes
the game's files also specifically list them as sublegendaries

>>30226407
Legendary is a meaningless term now, Type:Null and the Ultra Beasts are legends too.

Tapus, UBs, Null and Silvally are sub-legendaries according to the code.
Pokemon like the Birds, Beasts and Golems are also sub-legends, so it's honestly debatable considering the aforementioned UBs and Null Line.

>>30226487
Type: Null at least fits the same as Mewtwo and Genesect as a pokemon.

>>30226487
>Type:Null
>legend
wait what?

>>30226407
I was just thinking about this earlier. Between these, UBs, Null and the box legends, that's a fuckton of legendaries. And I thought Diamond/Pearl had overdone it way back wheb

>>30226407
They are aspects of the great spirits conscience. The island challenges exist as a distraction from Alola's true nature until the time comes when the islands are cleared of vegetation by the Bohrok hordes.

>>30226597
It's categorized the same way as the legendary birds, beasts, golems, and so on.

>>30226628
Is Necrozma Maukta?