The February issue of V Jump magazine will be announcing this Saturday that a major Digimon character will be returning to the series in Digimon Xros Wars: Toki o Kakeru Shōnen Hunter-tachi beginning January 8th.
Taichi Yagami (or Tai in the English version), will be the returning character and will appear as a new and powerful foe. Previously Monthly Newtype had revealed that the anime will be bringing some of the characters from the various seasons as Digimon Hunters.

source:http://www.jpopasia.com/news/former-digimon-hero-to-return-to-digimon-xros-wars::9589.html