Cecelia was Pegasus' childhood sweetheart. They first met at a party hosted by Pegasus' businessman father in Las Vegas fourteen years before the Duelist Kingdom event. At that time, Cecelia and Pegasus got married, and as an artist, Pegasus often sketched portraits of his beloved.
Tragically, Cecelia passed away from an illness shortly after their wedding, at the tender age of 17. This loss drove Pegasus to seek a way to bring her back, leading him to acquire the Millennium Eye from Shadi. Pegasus' deep affection for Cecelia was later revealed to Yugi Muto and his friends when they discovered Pegasus' diary, which detailed his emotions.
Pegasus' reason for putting Yugi and his friends through harsh trials to take over Kaiba Corp was to use its holographic technology to recreate Cecelia. In the English dub, this motivation was explained as combining the power of the Millennium Items with Kaiba Corp's technology to resurrect Cecelia.
(Source: Yu-Gi-Oh! Wiki)










