The Lightning Aura Rod, Cane, and Staff are unique summoning items that summons a Lightning Aura sentry minion with an appearance of an orb hovering over a small base at the area clicked. Each sentry produces a circle of lightning aura centered on its base that damages enemies repeatedly as they go through it. The Rod is a purchasable item from the Tavernkeep for 5 Defender Medal, the Cane for 25, and Staff for 100.
Lightning Aura weapons completely ignore enemy defense, regardless of its defense rating. The Lightning Aura Rod, for example, always inflicts around 4 damage on any enemy.
The Rod is available by default. The Cane is purchasable after defeating one Mechanical Boss such as The Destroyer, Skeletron Prime, or The Twins and the Staff becomes purchasable after defeating Golem. The three different versions function identically to each other, but with varying statistics, with the Staff being the most expensive and the most powerful.
These weapons cannot be utilized by the player outside of the Old One's Army event until the Old One's Army has been defeated at least once in the current world.
During the Old One's Army event, enemies drop Etherian Mana that can be collected and is used in the placement of multiple Lightning Auras that remain permanently until the event is over. Etherian Mana cannot be used outside the event and disappears from the player's inventory after the event is completed.
The best modifier of Lightning Aura Sentries is Demonic, as they do not have knockback and cannot gain modifiers that alter it.
Lightning Aura sentries are affected by the Monk Armor and Shinobi Infiltrator Armor set bonuses, which increase their attack rate and add a chance of dealing critical hits. The critical strike chance of these sentries will always be locked at 25% for the Shinobi Infiltrator and 16.7% for the Monk, and will not be boosted by the weapon's modifier or any other boost to critical strike chance.
- A Lightning Aura Sentry can be placed next to other Tavernkeep sentries, but it is not possible to place another Tavernkeep sentry inside an existing lightning aura. Therefore, it is best to cluster various sentries together and place the Lightning Aura last.
- The Lightning Aura's maximum radius is 9 tiles, with the top 'orb' being in the 10th tile up from the base. If summoned in an area less than 10 tiles (blocked by either platforms or blocks), the Lightning Aura shrinks, down to a minimum radius of 3 tiles, with the orb inhabiting the 4th tile above.
- The Lightning Aura requires a line of sight from the orb to any enemy inside its attack radius in order to damage them. Summoning a Lightning Aura in an area less than 10 tiles tall places the orb inside a block, rendering most of its attack range moot; though it will still damage enemies inside of its aura. While platforms decrease the range of a Lightning Aura, they will not block line of sight, allowing the aura to function normally.
- Dungeon Guardians, and any other enemy that can possibly have over 999 defense, are excluded from the Lightning Aura's defense breaching ability, and will cause the Aura's damage to be reduced like any other weapon.
- The aura will occasionally destroy projectiles fired by Caster AI enemies.