Yes, it's five mana like Hour of Eternity but it isn't rocked by bounce effects
Its important to note that prowess stacks, so if your creatures already have prowess, Narset gives them an extra instance
According to the domain registry, their domain was registered in 2018
Just casting this as a five-drop and following up with just about anything is already devastating enough before you even consider plot
Sure, many older cards from the first few years of the game have been since reworded for clarity and to conform with modern interpretations of Magic rules, but thats hardly a surprise
This largely eliminates the need for mana acceleration, but a little more mana means more opportunities to attach Equipment and activate other abilities