Well, thats because its a Shiny version of Latias, and these special Pokmon types often have a different color scheme, which really makes them stand out
Given how easy it is to create the Darkstar token and that it doesnt cost any additional mana, Rufus Shinra is a great card for giving you continual fodder for your sacrifice outlets, but also just for good board presence
You travelled to made-up worlds of wonders and, for some reason, it was always heavily inspired by the Middle Ages
A 5-mana 5/5 with First Strike and protection from Multicolored that makes you discard every turn would probably be a 2.5 at best thats a huge downside, even on an efficient creature
You don't choose which type of permanent any other player has to sacrifice
Or it would do, except that fans in the r/CompetitiveEDH subreddit found a way around this drawback as soon as Noctis was revealed