The COVID-19 crisis has highlighted elderly people as a vulnerable and excluded community, and connecting to the younger social media generation requires a shift in intergenerational storytelling performance. Recent research on multimodality has emphasized its benefits for the interactional process in storytelling. This study examines three aspects of storytelling -- participation, multimodality, and emotional interaction -- and uses co-creation and multimodal discourse analysis to investigate two questions: (1) "To what extent can intergenerational storytelling benefit older people's community engagement?" (2) "In a globalized world, how do children's relationships with modalities create new lifelong learning opportunities for elders?" Qualitative data were collected from pre- and post-session discussions from six storytelling sessions, video recordings made by the participants, and multimodal artwork created by the children after each session. The results reveal (1) that older participants had to adapt their multimodal storytelling, (2) that children preferred co-participatory multimodal storytelling, and (3) that co-participatory multimodal intergenerational storytelling benefits preschool and elders' well-being.