Ancients of War summon units as they approach your base. “Ancients like their grove quiet and undisturbed, so get off their lawn!”
Ancients take double damage from Siege Minis which makes them good counters. Spiderlings and Harpies also get summoned in the fight, so AoE spells and anti-air Minis will help.
For every PvE mission, there is a campaign version and a Heroic version. When you first begin the game, you can only participate in campaign missions. Upon collecting 50 sigils, you will then unlock Heroic missions.
Campaign missions will grant rewards after the first successful clear with ANY family. Heroic missions must be completed with EACH of the 5 different families in order to receive the mission rewards.