During the night you can choose following stackable upgrades:
Upgrade King Attack (max x10)
Increases the King's attack damage by 7%.
Upgrade King Regen (max x10)
Increases the King's health regen by 0.006% missing health + 0.006% max health
Upgrade King Spell (max x10)
Increases your King's AOE ability damage by 7%
Each king starts with the following spells:
Attacks deal 12-20% current health Pure damage depending on Upgrade King Attack
Uses mana to unleash bouncing lightning bolts that deal Pure damage.
Gains 1.3% damage reduction for every 1% damage taken this wave.