Visual storytelling is a widely practiced educational activity that encourages children's verbal and figural creative expression through both narrative and drawing. This study investigated how transforming children's drawings into multimedia formats--by adding sound effects, animated presentation, or a combination of both--impacted children's affective reaction and creativity in storytelling. An interactive prototype was developed to apply multimedia transformations to children's drawings when they experienced creative blocks. A mixed-methods approach was employed, involving 80 children aged 8 to 10 years, who were randomly assigned to four groups: a control group and three intervention groups subjected to sound effects, animated presentations, and a combination of both. Emotional and creative outcomes were assessed across these groups. Quantitative analyses showed that the groups subjected to the multimedia transformations exhibited significantly stronger positive emotions and creativity compared to the control group. Qualitative findings further revealed that children in the multimedia transformation groups experienced greater immersion due to the sound effects, which encouraged more detailed story elaboration, while the animated presentations facilitated the exploration of cause-and-effect relationships, inspiring more expansive storylines. The combination of the sound effects and the animated presentations was observed to provide the most comprehensive support, enhancing positive emotions, boosting independent creativity, and helping children overcome creative blocks in visual storytelling without introducing new content from external sources. These findings inform the design of storytelling-assisted systems and broaden understanding of how multimedia supports creativity and independent problem-solving through emotional enhancement.