Bosses will usually enter a charge up phase where a secondary bar appears
Cosmic Eclipse also helps the cards reputation because the set is already remembered for standout artwork and collector-friendly pulls, meaning Rosa does not feel like an isolated chase card from an otherwise forgettable release
When a white deck leans into those strengths, it becomes surprisingly hard for opponents to break through
Unsurprisingly, plenty of fakes were 'discovered' along the way as well
In fact, many cards have retained their value or seen a pretty substantial increase in value over the years, which is why there is a huge market of people either collecting them or trying to sell them
BPhillipYork: This would roll out pretty quickly and let you start drawing a lot, if you deck is built around aggro artifacts, artifact ramp, and Treasure you could conceivably be drawing a lot, very quickly