You forgot to define what a pseudo element is.
My definition:
A Pseudo element is a theme that is completely encompassed by a single elemental category.
Example:
Other(Void) [Other can be the lack of elements. No other category can do this.],
Other(Energy) [Other can be the presence of themes from all elements. No other category can do this.]
Not examples based upon this definition and the definitions of the themes provided:
Divine (so far it is defined just as high alternate costs with short durations),
Acid (Death but also Fire [Fire Shield], Life and Time[Poison]),
Blood (Max HP costs fit Darkness, Death, and Fire),
Spirit (Again HP costs fit Darkness, Death, and Fire)