AncientSphinxmon is a Mega Digimon.
In Ghost Game, AncientSphinxmon appears in the human world, forcing humans to guess a riddle, if one who did not answer, they will turn into stones for his pyramid to revive an ancient Digital World and Pharaohmon. The victims includes Ruli's friends Hiro, Kiyoshiro and Kaoru. After knowing this, Ruli inquires Mummymon, suddenly AncientSphinxmon's pyramid appears in front of them. Ruli switches the battlefield to the Digital World, Angoramon then Warp Digivolves to Lamortmon and fights against AncientSphinxmon, but was knocked out by the latter. On the edge of crisis, Lamortmon asks AncientSphinxmon if there is a piano, and talks about how it’s sounds like, desserts, tea, hot springs, travelling, culture and more. As Lamortmon's time is about to run out, Ruli begins to do the same. Angoramon wants to learn more, and Ruli isn't done finding her perfect hobby yet. Ruli and Lamortmon's strives encouraged Lamortmon to Digivolve to Diarbbitmon, Diarbbitmon overpowers AncientSphinxmon, then AncientSphinxmon uses his special move "Necro Eclipse" in order to send Diarbbitmon into the world of death, but when AncientSphinxmon is about to push Diarbbitmon to the crevice, Diarbbitmon lifts his sword and pushes AncientSphinxmon into the crevice, leaving AncientSphinxmon to scream in distress and being swallowed by the power of death, although Diarbbitmon tries to save him. All the victim humans turns back to normal after AncientSphinxmon's demise.