First appearing in Avengers Vol 1 #10 in 1964, Immortus was a mysterious traveler from the far future. It took a decade for Marvel to confirm this was the oldest incarnation of Kang, who enjoyed manipulating history. Eventually, the pair broke off into separate variants so Kang could follow his own path.
This variant also appeared in Quantumania, blue-faced, notable for his deep voice and clearly the one in charge. He’s able to put the other variants in their place as he seems set to lead them in the buildup to the Kang Dynasty.
This variant is a bit tricky as some comics claim he’s Kang traveling to the past while others say he’s a younger version of him. Either way, he was an inventor using his knowledge of the future to become mayor of a small town in the early 20th century. In many ways, this Kang helped accelerate human technology, which also allowed him to secretly control it.
Loki Season 2 appears to use Victor as a late 19th-century scientist Loki and Mobius investigate. How he plays into the overall saga of Kang will be a key part of the season.
These are just the Kangs introduced so far, as there are literally millions about the multiverse who can cause problems. Thus, Loki Season 2 may be only the start of the Kangs plaguing the MCU in Phase 5.