The Ballista is a primary weapon in Sanctum 2 that is unique to TSYGAN; it is only available as part of the Road to Elysion DLC. It holds eight bolts that travel at high velocity and can be charged using the primary or secondary fire to deal more damage. The last bolt in the magazine gets a large damage multiplier, as a fully charged shot from TSYGAN inflicts over 22,000 damage on a body shot without perks.
The primary fire launches a bolt that deals high damage. The secondary fire launches a bolt that shocks nearby enemies, but inflicts less damage and consumes two ammo.
Secondary fire bolts can be fired into the ground at choke points to damage fast moving enemies like Snorkers or Runners. They will also stick to enemies themselves, allowing the AoE to move along with the crowd.
The AoE range for this effect can be increased by the perk Long Range Specialization.