This screen is where you can summon heroes using different resources.
Gem Summon
The Gem Summon screen allows you to summon rare or ultra-rare heroes (3-stars and above).
Tap the 1 FREE Summon button to get a single rare or ultra-rare hero for free. Once you use this option, you’ll have to wait 66 hours before you can use it again. If you’d rather not wait, you can use a summon scroll to summon another hero right away.
The 10 Summon option will summon 10 rare or ultra-rare heroes for 2500 gems.
Using either option will also net you crystals. Using the Free Summon or Scroll Summon options gets you 1 crystal, while using the 10 Summon option gets you ten crystals. Crystals can be used in the Divine House to purchase rare materials and heroes.
Friendship Pt. Summon
Another way to summon heroes is to use Friendship Points. These are earned whenever you use a hero from your friends list when selecting from the Ally Assist menu prior to battle. You can access the Friendship Point Summon option by swiping left or right on the Summon screen. Note that unlike Gem Summon, Friendship Point Summon only grants 1-3 Star heroes.
You can see how many Friendship Points you will be awarded in the Ally Assist screen, next to each hero’s Squad Level. Note that you will only be awarded those points if you win the battle.