Skill 1 - Summon Zombie (Slow-moving, but very tanky)
Upgrades - Zombie Health, Zombie attack power
Skill 2 - Summon Spectre (Fast-moving, very fragile)
Upgrades - Spectre Speed, Spectre attack power
Skill 3 - Minion Explosion (Kill all existing minions to cause a radius of damage around them)
Upgrades - Explosion Radius, Explosion Damage
Passive 1 - Number of minions (1, 2, 3, 4)
Passive 2 - Minion Defense (0, 2, 4)