Starting with Ravana. they all have a Tertiary element. And some of them have elements that are not standard.

Tsukuyomi is Light AND Dark. Both related to the phase of the moon she is in.

Ravana's 3rd is Ice. The morphos cast ice spells.

Bismark's is Thunder.

Sephirot's Primary's are Earth and Wind. Water is his tertiary.
Sophia's Tertiary is Ice.

Lakashmi (who I spent a TON of time trying to figure out) is Fire, Light, and Water. It takes the extreme version to figure out her aspects.

Arguably, even the main 6 have low degrees of a 2nd element.