Last appearance of Kara Kent before she joined the legion.
Lois gains Clark's powers when Jor-El swaps them, this is very similar to the comics where Lois gains his powers and becomes Superwoman. The first appearance of "Superwoman" in a DC comic is a story in Action Comics #60, where Lois Lane dreams that she has gained superpowers from a blood transfusion from Superman and launches a career as Superwoman.
The Orion referred to is actually based off the comic book character of the same name. Orion was the son of Darkseid who was swapped with Scott Free(Mr. Miracle) and raised by Darkseids counterpart High Father on New genesis as part of a peace treaty. Scott was then raised by Darkseid on Apokolypse.
Final mention of Lana Lang (Kristin Kreuk ) by name on the series. Lana does appear in archive footage in the finale but is not mentioned by name.
This episode introduces a round table of villians that appeared as members of The Legion of Doom : Black Manta, Captain Cold, The Toyman, Dark Archer, Solomon Grundy & Roulette.