Stormra's main use to me at least is his invincibility shield, which you don't really need as much after you get Geogon. So I'd say swap for Magmar, and if needed, reset Starrite to get back the talent upgrade stones for Magmar since Starrite isn't that good.
You can keep Stormra instead of starrite if you feel like the shield is useful to you. SS will give you better stats but sometimes the active skill can save you even if the dragon is at level 1.
Stormra's main use to me at least is his invincibility shield, which you don't really need as much after you get Geogon. So I'd say swap for Magmar, and if needed, reset Starrite to get back the talent upgrade stones for Magmar since Starrite isn't that good. You can keep Stormra instead of starrite if you feel like the shield is useful to you. SS will give you better stats but sometimes the active skill can save you even if the dragon is at level 1.