Help How to do with this Beast Soul no have idea

[Keenantot]

how to manage this Beast Soul... feed? and level?

[BrotherVT]

You need to "Promote" the beast. If you look at the icons you have on the bottom screen, there is an icon that says "Beast Soul".
Click on it, and you will also need Dragon Essence, which you can either buy from the Fate Shop for 35 Crystals each or buy the packs Dragon Essence Pack (10% Off) for 630 crystals and get 20 Dragon Essences from it or get the Dragon Essence Pack (20% off) for 8,400 Crystals and get 300 from it.
You can also get bound Dragon Essence from NM Dungeons starting from Sacrificial Relics dungeon and higher.

When promoting, there is a chance to get a regular hit, a critical hit or a lucky hit. You can increase those chances by boosting your attempts, which is 50 crystals for 15 boosts.

When upgrading your Beast Soul, certain beasts will let you get the skills from them. Example is 5% Lifesteal from Seiryu beast soul which is a lot of money to get in my opinion. >.>