Okay so I am making this short and sweet. Tyrain is based on scorpio. Think about it Scorpio (Tryrain) is sent off by Gaia or Artemis depending on the version of the myth that you want to go off of who is a powerful female entity (Salem) to kill a strong, powerful, and dangerous hunter (Ruby) who is either a huge threat to the animals of the earth in Gaia's case (or a huge threat to her Grimm in Salem's case) or is just someone that she really doesn't like in Artemis' case (I mean Ruby did hurt one of her key players in her plan so I don't think Salem is very fond of the little crimsonette).