You can learn more about the evolution mechanic right here.
From Wizards:
Wizards of the Coast is thrilled to have officially launched Kaijudo – Evo Fury, the first expansion set for Kaijudo!
Evo Fury marks the introduction of an entirely new mechanic to the game: evolution! Now players will be able to boost their already awesome creatures to new heights in battle and show opponents a new way to duel. The game will never be the same after Tatsurion is unleashed as an evolution creature in the battle zone!
Kaijudo – Evo Fury contains 60 all new cards with representation from all five civilizations, allowing players to truly customize their decks. The Tornado Generator competitive deck (MSRP $11.99) contains 40 cards plus a code card and features one super rare and one very rare foil card. Evo Fury booster packs (MSRP $3.99 per pack) each contain nine cards plus a code card. Code cards from the competitive deck and booster packs can also be used to unlock cool creatures in the Kaijudo Online game and creatures from this set will be featured in the Kaijudo TV series that airs Saturdays on The Hub TV Network.
