Ikkitousen Xtreme Xecutor [TV]

Ikkitousen: Xtreme Xecutor is the fourth season of the anime, continuing off from where Ikkitousen: Great Guardians left off. Xtreme Xecutor follows the story of The Great Fighters Tournament, held by far to the east over seas, but it was a ploy as the participants are ambushed, by a reborn Teni who has acquired great new skills since the last time seen. She is following a mysterious but familiar shadow, as this strange person plans on making history happen, causing all fighters to meet their untimely death. Who is this strange shadow, and why does it want to cause the girls fates to be realized?