I know the Grim is a myth pet, and sea dragon is a fire pet- but I think sea dragon has all universal help on the pet.. I really liked my sea dragon, was always my number one pet until i hatched and got my spider. It's really just a matter of preference on apperance.. You can make any pet have the stats you want with hard work.. So pick the pet you like overall the best and go from there.
Hey the grim is a balance pet with a myth trap card? kinda different but it looks like it has universal talents like the dragon, so either way you go, looks good :)
