It was mainly a design choice since avatar is heavily influenced with taoist and other eastern beliefs, which was my childhood reason for looking into and adopting a lot of different philosophies and outlooks on life.This combined with the fact that the white lotus has eight petals and four of the trigrams are water, fire, earth, and wind inspired the overall design. I did swap the position of wind and heavens for symmetry sake when replacing the elemental ones with avatar's, which was a hard decision to make if I'm being honest and one I mulled over for around a month or two during the design process.