You can get the Dragoncrest Greatshield Talisman when you reach the Haligtree. Progress further through Elphael, Brace of the Haligtree, until you find the Drainage Channel Site of Grace.

You can get the Dragoncrest Shield Talisman at the Bestial Sanctum. You can get here by travelling through Caelid or by using a teleport in the small lake north of the Third Church of Marika ...