Regarding the dual aspected primals, I just want to point out that Ravana and Bismarck actually encompass half of the wheel, though certain elements are not as prominent.

Ravana is the bigger offender there, not directly using Blizzard attacks while using fire and earth attacks. But the Adds use ice attacks (and Ravana battle the Ice Aspected Shiva first)

Bismarck on the other hand does use all three via his weather effects, even then he uses Water attacks more often with the Vanu adds using Wind attacks as well as the only in battle clue to its aspect (Wind and Water) being the Sanuwa adds.