Alright niggas, alchemy time.
For alchemysts, there where only seven "planets", and they are
>Sun
>Moon
>Mercury
>Venus
>Mars
>Jupiter
>Saturn
Since Sun and Moon are actually no real planets, they are not UBs, so they are indeed Solgaleo and Lunaala.
After them, every UB represents a planet, so it comes like this:
>UB-01 ??? - Lillie -> Mercury.
>Traditionally speaking, Mercury is the epitome of fluid. This planet represents the strength of the movement, intellect and transformation.
This explains why its similar to a Jellyfish and why it can change its form, according to the website.
>UB-02 Beauty - Lusanime -> Venus
>When it comes to alchemy and its symbolism, planet Venus traditionally rules over the copper. Venus is strongly associated with femininity and beauty, but when we speak about beauty keep in mind the philosophical aspect of the story – beauty is here connected with the ability to absorb and reflect light.
Explains the feminine form. Also explains why is Moon exclusive, since Moon is linked to the woman in alchemy.
>UB-02 Expansion - ??? -> Mars
>Mars is symbolically associated with iron, although probably the first association for this planet is masculinity or virility (just like Venus and its association with a femininity). Therefore, it is not surprise that Mars rules over the male energy and raw power, while on a deeper, psychological level this planet rules over the primary instincts and basic human needs.
Just like the one before, it also explains its masculine form. Also explains why is Sun exclusive, since Sun is linked to the man.
(Post is getting too long, I'll continue in the next one)