Bombardment

Bombardment is a Conviction skill, unlocked at level 61.

In-game
When activated, a targeted point (anywhere within 60 yards) is hit by a distant catapult shot after a brief delay. Subsequent shots have a 0.4 seconds interval, to a total of 5 shots for 570% damage as Physical each, and scatter, hitting the random points anywhere within 24 yards of the initial impact point. All 5 shots hit in 2 seconds.

The barrage shots may intersect with each other.

Runes

 * Barrels of Spikes: The damage of each barrel is increased by of the Crusader's  damage. Visually, stones are replaced with barrels.
 * Annihilate: The damage type changes to Fire and the spheres will critically strike foes foolish enough to be damaged.
 * Mine Field: The damage type changes to Fire and each impact scatters mines onto the battlefield (anywhere within 30 yards of the impact location). The mines explode when enemies walk near them, dealing  damage as Fire to all enemies within  yards. Mines last up to 6 seconds after they are laid.
 * Impactful Bombardment: Instead of 5 shots, a single blast is fired. To compensate for this, the damage dealt is increased to and its radius increases to  yards. Note that the damage of a single impact is more than the combined damage of five normal blasts.
 * Targeted: The damage type changes to Holy, and blasts no longer scatter randomly, instead seeking targets nearby (if possible, they continue to fall on the initial target, provided the latter was an enemy instead of location). Potentially, all five blasts can pinpoint the same location.

Passives

 * Lord Commander: reduces cooldown by 35%.

Non-rune enhancements

 * The Mortal Drama (Legendary Two-Handed Flail): increases the damage of Bombardment by 400-500%, and doubles the amount of Bombardment shots (normally to 12, or to 2 with Impactful Bombardment rune). The intervals between shots do not change.
 * Belt of the Trove (Legendary Belt): increases the damage of Bombardment by 400-500%, and every 4 seconds, automatically directs a cooldown-independent Bombardment on a random enemy within 40 yards.
 * Thorns of the Invoker Set (Set Bonus for 4 items): after casting Bombardment, the Crusader takes 50% reduced damage for 20 seconds.

Trivia

 * Interestingly, in game files the graphics for this skill are dubbed "Defensive Shell".

Development
Prior to the Thorns buff, Barrels of Spikes rune was instead called Barrels of Tar, slowing affected foes on impact and leaving pools of tar.