What I'm wondering is why this isn't a mono card (in-element ability), duo card (off-element ability), or a duality card (duality ability) but a semi-duality card with a mono ability.
The mechanic of duality cards are that they are mono cards for two elements, as in they require only one element.
The mechanic of mono cards are that they are mono cards for one element.
The mechanic of duo cards are that they require both elements.
The mechanic of a semi-duality card is that they require exactly one element; they are mono cards for one element and duo cards for another element.
The problem is that this mechanic has no thematic justification.
