Hi! In the arena game, pieces are combined by purchasing three of a kind. If you already have two of the same creature, buying a third will automatically combine it into a "two star" version of that creature. Then, if you do that two more times for a total of three "two star" creatures, they'll combine again into a maxed out "three star" version. You don't need to click and drag anything, just invest in multiples of the same kind of guy. C:
