A third way to improve your characters is to evolve them, and evolving them is done by using soul stones. You’ll need all of the soul stones for a card just like you would to summon them. The number varies depending on the rarity/star rating of a card – for example, a one star card will require 20 soul stones, compared to 100 for a three-star card.
Another easy way to get soul stones is if you end up finding a replica of a card you currently have. Oftentimes these come from the chests. If you end up with a replicard, it will instead be broken down and transformed into a number of soul stones to be put toward a future evolution.
Wanna know where to get the soul stones? Tap on any of the heroes that have not been summoned, and right in the pop up that appears it will say what chapter, and what stage in that chapter to play in order to earn a new hero. Once you find the stage, farm the hell out of it until you have all of the necessary soul stones.
Later on in the game you will unlock the merchant. Go here to buy new equipment but most importantly, go here to purchase rare characters for far less than you would otherwise spend on a gold chest. Don’t bother spending your gems on refreshing the store, though; better to save those gems for buying rare characters from the store.
After you beat one the first chapter you will unlock the elite version of that chapter, and so on and so forth for subsequent chapters. Play the elite versions to get more and better prizes compared to the standard versions. Most of the elite dungeons are not even that much harder – they just have more battles to fight compared to the other ones. Plus for every round that you beat, you will earn 10 free gems.
Once you unlock the arena, you’ll need to pick an enemy wisely if you plan on winning. Pick an enemy whose power level is the same as or less than yours, but make sure that your skills are upgraded as high as they can go because a LOT of players will completely neglect skills. And don’t forget to always keep your defensive team up to date.