most rare card in clash royale User blog:Captain GLeen Du Grande/Ranking the cards | Wiki Clash Royale Devs When Deciding

Once per turn: You can remove a number of Arcadian Counters from this card, then target 1 monster you control, and if you do, reduce or increase it's Level equal to the number of Aurora Counters removed

A little later on and this will also find any creature you might want or a more exotic land if for some reason you need that instead

Commander Commander (CTRL to add secondary) Combat Combat Celebrant If this creature hasn't been exerted this turn, you may exert it as it attacks

The wild popularity of the set sold preorders out fast, with stock only now starting to return to shelves and online retailers

Three toughness is nice but this is pretty bottom of the barrel stuff otherwise

Base Set Trainer Cards : Positioned as valuable for their gameplay and historical importance