Theory for Ultra Beast
UB-01 and Lillie are very similar in resemblance. It is already theorised that Lillie is UB-01, and this theory is supported by the fact that the official Sun/Moon site states that UB-01 can change shape, implying the possibility of it changing into human form, it also states that “its movements resemble those of a young girl”. The word “mysterious” is also used to describe both Lille and UB-01.
Lillie, Lusamine, and Gladion all look similar in appearance. They share similar features, particularly blonde hair and green eyes. It is plausible that they are related.
Assuming that Lillie is an ultra-beast, and all three are related, it is plausible that they are also ultra-beasts. It has been confirmed that multiple ultra-beasts exists, since the English trailer says “Ultra-beasts” rather than using the singular form.
The description of UB-01 says “it’s constantly changing shape”. This would imply that it is difficult for the ultra-beasts to retain a single form, such as that of a human. In the footage of Gladion his hand is constantly twitching, which could possibly be due to his difficulty retaining his human form.
The three also have similar opinions regarding Pokémon battling. In the description of Lillie on the official Sun/Moon site says “She’s not fond of making Pokémon fight in battle”, suggesting she does not like to see Pokémon harmed. Lusamine shares this interest in protecting Pokémon as she is the president of the Aether foundation, which is designed to protect Pokémon. Lusamine also states “I will be like a mother to all of these poor Pokémon” again illustrating her caring for Pokémon wellbeing.
While Gladion seems to be less inclined to protect Pokémon as he is a member of team skull he still hints toward caring for Pokémon by saying “You’ll just get your Pokémon hurt for no reason”. Gladion also uses Type: Null, which is a synthetic Pokémon. The use of a synthetic Pokémon could be in part due to his not wanting to hurt a real Pokémon when he battles.
The origin of the ultra-beasts is unclear, but it is possible they may have extra-terrestrial or extra dimensional origin. The wormhole that UB-01 emerges through suggests this. Lusamine also says “Even Pokémon from distant worlds, far from the Alola region are worthy of my love”, which could merely be referring to other regions, but the choice of words is suspicious.
The proposed theory is that, given this evidence, it is plausible that Lillie, Lusamine, and Gladion are all ultra-beasts, and that the ultra-beasts, being new to our world, and disliking the harm caused by Pokémon battling, have some desire to protect Pokémon.
~ Signed Mystery Incorporated