The etymology given made me wonder if charisma is related.

No, Gk kharisma 'divine favor' (cf. eucharist, and modern Gk eukharisto 'thanks') is ultimately from the PIE root *gher- which also gives us English yearn, while koros 'boy' is from the root *ker- 'to grow' which gives Latin Ceres 'goddess of grain' (whence Spanish cerveza and cereal) and cresco 'to grow, wax' (crescent) from creo 'to bring forth, create'.