However, if a Heart's Egg's owner is burdened by worries and doubts, the egg will turn into an X-Egg and eventually hatch into an evil and aggressive X-Character, and go on a rampage with its powers. Their owner is usually their first target. These characters are usually much stronger than their egg incarnations. The X-Characters are enemies in Shugo Chara!. These creatures are invisible to normal people, and only owners of Guardian Characters and pure-hearted children can see them.