Evolve is a new feature of Transformers Legends added for campaign episodes. The first campaign episode is Covert Operations.
There are currently 4 stages of evolving. Each new stage gets +10% Stat Bonus for each Max Level Card that was used for Evolution, new card look and art, increased Battle Bonus, increased Max Level, and increased Stats. Fully Evolved Cards get Battle Bonus. Stage 4 cards also get an animation.
Evolve is essentially multi-staged trans-scan. Evolving requires two compatible cards and produces one, more powerful card. Also similar to trans-scan, the base statistics of an evolved card are partially dependent on the cards used in the evolution process. When a card is evolved, it's statistics are increased both by a pre-determined amount and evolve bonuses. Evolve bonuses are determined by the cards used as inputs. For fully upgraded input, 10% of the input's statistics is added to the evolved card. For input that is not fully upgraded, 5% of the input's statistics is added to the evolved card. The inputs do not have to be of the same upgrade level. However, note that the game does not permit two level 2 cards to be evolved together to produce a level 4. Cards must be evolved in the following sequence:
To see a list of all known evolve characters, go to the associated card list.