Ballista

The Ballista is a weapon in Doom Eternal. It is similar to the previous game's Gauss Cannon, and runs on Energy cells. The Ballista is acquired in the Fortress of Doom after completing Doom Hunter Base: it is presented as a mission objective to get it, so it cannot be missed.

Codex
''The weapon of choice for Sentinel marksmen. It is said in Sentinel battle lore that a single battalion of archers defended the walled city of Illkana for ten days and ten nights armed only with their Ballistas. A precise weapon, the Ballista fires a twin beam of superheated Argent, vaporizing its target on impact.''

Description
By default, the Ballista fires a single high-powered shot with a fairly low fire rate but pinpoint accuracy. The basic fire mode, regardless of the equipped mod, costs 25 Cells per shot. It is best used as part of one-two combos with another weapon, as all of its attacks either have slow fire rates or need to be charged up. It is also excellent for targeting the weak spots of enemies that have them, though less ammo-hungry weapons like the Heavy Cannon with its Precision Bolt mod, the Combat Shotgun with the Sticky Bombs mod or the Rocket Launcher are generally more appropriate for this.

Arbalest
The first mod is called Arbalest. This is very roughly analogous to the Gauss Cannon's Precision Shot, but has a weaker zoom effect without a "sniper scope" screen overlay, and focuses primarily on damage. It has the same energy cost as the default shot at 25 Cells, but has an attached charging and reloading time, and slows down the Doom Slayer's walking speed while it is being charged or while a charge is held. The walking speed penalty can be negated with the "Full Speed" upgrade, and the Mastery removes the pause between firing and being able to charge a new shot.

When fired, it shoots out a dart-like projectile with similar speed and accuracy to the primary fire. After a short pause this projectile explodes. It appears to deal damage twice: if the initial hit kills the first enemy struck, the bolt will go right through it without exploding and can hit a second. The explosion is large and very powerful: a single shot is quite capable of killing a Cacodemon instantly.

All attacks with the Arbalest deal 50% bonus damage to flying enemies.

Destroyer Blade
The Destroyer Blade approximates Siege Mode, but again differs in the details. By default Destroyer Blade uses 50 Cells and must be fully charged before it can be fired. While it slows the Slayer down, unlike Siege Mode it does not lock him in position even if it is totally unupgraded.

Rather than Siege Mode's concentrated beam, the Destroyer Blade fires a off a broad horizontal line of Argent Energy that is able to hit several clustered targets. The two upgrades add a peripheral blast effect that can stagger demons with a near-miss, and increase the charging speed: the latter is vital to get the most out of the weapon.

The Mastery, Incremental Charge, removes the requirement to fully charge the weapon before it can be fired, instead giving a three-phase charge with the damage and width of the beam increasing with each step. The increments each have their own energy cost: 16 for a level one charge, 33 for level two, and the usual 50 for level three.

Ammunition
The Ballista shares its ammo pool with the Plasma Rifle. The player can increase his max ammo cap by using Sentinel Crystals and allocating its power to "Ammo" subsystem.

Weapon Skins
As with most other weapons in Doom Eternal, the Ballista has several weapon skins available.

Trivia

 * Ballista and Arbalest were both the names of bow-like weapons: the former a torsion-powered siege engine, the latter a type of heavy crossbow.
 * The passive Cacodemons flying around in the distance in Hell On Earth and Super Gore Nest can be killed and count towards the Arbalest Mastery.
 * Similar to the Gauss Cannon, the Ballista's recoil can be used to the player's advantage, launching you in the air as far as a double jump, and launching you even farther if you're moving backward.
 * The "Battle Mech" skin, bears striking resemblance to Neon Genesis Evangelion's EVA-01. However, it is unclear if this is a mere coincidence.

Ballesta (Eternal)