The ballista is a weapon introduced in Doom Eternal. It fires a single straight shot, similar to the gauss cannon. The first mod, Arbalest, can be charged to fire a shot that sticks to its target before detonating a few seconds later. The second mod, Destroyer Blade, charges and unleashes a wave of Hell energy that cuts through demons as it travels.
The ballistas are the weapon of choice of Night Sentinel Marksmen. The weapon is very powerful as a battalion of Night Sentinels managed to defend a city of Ilkana from a massive horde of demons.