This ability triggers only once each turn." If the ability granted by Well Rested triggers in an untap step, it goes onto the stack at the beginning of the next step (usually the upkeep)
This is an effect of attack, but its an effect applied to the player, their hand, or their deck, and not on any Pokmon
Another factor adding to the cards demand is the fact that it uses Fairy Energy cards
Ego Drain loses its downside when you control a fairy, while Nectar Faerie can give one of your faeries lifelink for a turn
Unsurprisingly enough, most of these wincons require quite a bit of set up, and it's going to be a tall order to include enough cards to make any one of them properly viable
Each serves a specific role that shapes how matches play out , and youll find out soon why these are essential