Castform has a bit of an identity crisis. When the sun is shining, it's happy as can be; when it's overcast, Castform is a fretter. If there's any kind of precipitation falling it's got a tendency to overreact to things, and it also has a fear of thunder. It is aware of this flightiness and does its best to watch itself, but still is happiest when provided with a steady light source. (Mami may want to invest in a nice lamp.)