While browsing through my old sketches, I came across a series of Robot Masters I drew, known as the Zodiac Masters.
They were based off the 12 animals of the Chinese Zodiac, and the weakness cycle is the order of the Zodiac itself.
Rat -> Ox -> Tiger -> Hare -> Rat
Sheep -> Dragon -> Snake -> Horse -> Sheep
Monkey -> Rooster -> Dog -> Pig -> Monkey
The designs were based on the respective Zodiac Digimons.
That's also a fusion of all 12 Zodiac Masters, into the "ultimate" being, Zogod.
If only I had a scanner... >_>
I will attach a short writeup of each soon.