creidne (fire emblem)
Larcei's replacement/substitute in Fire Emblem: Genealogy of the Holy War if Ayra was left unmarried or died before the end of the First Generation. Like many substitutes, she is notably inferior (stat-wise) to the character she replaces.
Notably, she is featured in the manga adaptation by Mitsuki Oosawa, being the only substitute character to do so, alongside her brother, Dalvin (who is Scathach's substitute.)