Ultraman Tiga Gaiden: Revival of the Ancient Giant (2001)

This is a direct-to-video special set many years after the end of the original Ultraman Tiga series, in which Daigo Madoka (host of Ultraman Tiga) has a son with Rena, named Tsubasa Madoka. Tsubasa is a member of the team featured in Ultraman Dyna, Super GUTS.