Hmm, Theran originally was meant to be a shapeshifting dragon that would have a humanoid form (that still looked quite draconic and a full dragon form). I gave him the name Theran because there was someone at an old job named Theron, and I connected Theron to Therian and then Theran Pendragon because he was also originally meant to be an author and curator of antiques, who would use his proceeds to fund the gang's activities. He basically came about because I wanted a dragon and this was before Lolo (the character) was a thing so he was the requisite dragon of the group.

His current role in the canon is still that he's involved as the legal advisor for Team Reading Rainbow who does write smutty romance stuff for fun so that part hasn't changed. He's always been a bit of a background character so he never really came up much.