Merlin spiral novels

"When a meteorite crashes near a small village in fifth-century Britain, it brings with it a mysterious black stone that bewitches anyone who comes in contact with its glow---a power the druids hope to use to destroy King Uthur's kingdom, as well as the new Christian faith. The only person who seems immune is a young, shy, half-blind swordsmith's son named Merlin. As his family, village, and even the young Arthur, are placed in danger, Merlin must...