Great Fairy Cotera
Great Fairy Cotera is one of four Great Fairies in Breath of the Wild. Her Great Fairy Fountain is located northeast of Kakariko Village. It can be reached by following the path up the incline at the northern edge of the village and then heading east past the Ta'loh Naeg Shrine into the small forest there.
To open her Great Fairy Fountain, Cotera will request an offering of either 100; 500; 1,000; or 10,000 Rupees depending on how many Great Fairies have been restored to power already. Once her powers have been restored, Cotera will upgrade certain pieces of Link's armor provided Link can meet the required materials cost.
For each Great Fairy restored to power, the Great Fairies' collective power is stronger, allowing each Great Fairy to upgrade Link's armor to higher levels. To upgrade his armor to the highest level, all four Great Fairies must be restored.