With excess Evos in your inventory, you can combine them into rarer evos that you may need for your heroes' ascensions! The following table below shows the list of Evos that would take to craft the following ascension materials.
See Evos for an entire list of evos and which heroes they are used for.
If you collect 10 Evos of the same kind you can combine them into one rarer Evo.
Once you reach Player Level 18, you can find the Crafting icon on the left side of the townhall main page. The Combine Evo Tab is also accessible when you open the hero profile of any hero from your collection, tap Ascend, and click on any evo in the list of required ascension materials.
Within the new window, the left hand portrait shows the list of evos that you have collected throughout the game. Tapping the icon of either a Larva, Sprite, or Monarch will bring up a window on the right hand side of the page, showing the type of evo to be crafted and the quantity of materials required from your inventory. Any insufficient items will be marked in red.