The Wishlist allows you to select the units that you would like to get in the Essential Summon.

You can select 5 units from each faction and increase the probability of obtaining them.

You will not obtain even higher probabilities by selecting only one unit from a faction so we recommend you use all 5 slots in each faction's Wishlist.

The Wishlist will only affect the Essential Summon probabilities and doesn't influence the probabilities of the Legendary Redemption unit obtained after 50 Summonings.