So in the advent that we get DLC in SV, it makes me wonder not only whether or not we'll see our third legendary/the Area Zero Entity, but how we'll go about its boss fight. Lemme put this into perspective: ever since Gen 7, we've had a boss fight that has had a direct upgrade to that gen's gimmick. Rayquaza technically does the same in ORAS by having its Mega Evolution not tied to a held item, but he doesn't Mega Evolve during his boss fight to my knowledge. But for the real examples:
- Ultra Necrozma: USUM's boss has a direct upgrade to Z-Moves by having a transformation accessed by its exclusive Z-Crystal and an all-powerful Z-Move that's effectively a Spirit Bomb.
- Eternatus: While we can't have a playable version like Ultra Necrozma, we can still consider Eternamax Eternatus as a direct upgrade to Dynamax/Gigantamax, making Eternatus the only Pokemon in history to reach a BST of over 1000.
- An exclusive Omni-type Tera Jewel that's Super Effective against everything and has only a weakness to Rock-type...which could be completely negated by an ability that allows it to heal from Rock-type moves used against it, which could make sense since jewels are just prettier rocks.
- Access to two Tera Jewels that allow him to mix-and-match type combos. It also has the ability to change the type of its Tera Jewels on the fly, much like the Legend Plate from Legends Arceus.
So if a game like this ever comes into existence, I’m so picking the grass starter and nicknaming it Groot.