Blast to the past is the 22nd episode of Super Digimon Xros Wars.
Ian and his team are lost as to why DarkKnightmon would open a portal to the human world. Ian and Sparrowmon begin looking and find out that they are at the Nazi concentration camp. The team chooses to hide from anyone in sight and then they see SuperDarkKnightmon looking for something then Ian says that they'll stop DarkKnightmon and reloads the Digi-Eggs and Digi-Xroses Flamemon, Pegasusmon and Nefertimon. Then Flamemon Knight and SuperDarkKnightmon rush into battle.
(Numbers indicate order of appearance. Bolded characters are fought by the protagonists, and italicized characters appear only as a voice or silhouette.)
People at the concentration camp