Lich's melee units

Lich's melee units consist of Marauders, Ravagers, and Stalkers. They are typical fantasy skeletons: relatively frail and numerous. These guys fall over quickly but also overwhelm your enemy by sheer weight of bodies. Their low resource cost plus lich armies ability to raise them from dead unit's corpses allows them to be a disposable yet somewhat effective wall on the front line. If your enemy is few in number and attack one target at a time, they can delay an enemy for a long time on the front line. They can be buffed by Gazul’s passives and other heroes have abilities/passives that synergies with them.

Upgrades
The ability of upgrading Marauders, Ravagers, and Stalkers is unlocked at academy level 1