>>117276689Even before the "I killed your mom" retcon Thawne had posed as Barry, killed Iris and when he tried to kill Foira Webb Barry finally had enough and killed him leading to the Trail of the Flash and immense damage to his reputation. Cold and crew might have had more appearances over the years but Thawne's been the "Shits getting real" when he shows up villain for Barry since the Bronze age.
Hell moving on to the Flash franchise as a whole. who was the villain used for Wally to overcome for Wally to overcome the mental blocks and comparisons to Barry that were holding him back, was it Captain Cold? No it was fucking Thawne.
Colds awesome and he's definitely up there in Flash's villain tier list but he and the Rouges Do not have the arch enemy relationship Thawne has with the Flash Family. Honestly Grodd might come closer to the secondary arch enemy than Cold.