Arbiter

Arbiters are hand-shaped enemies found in the Cavern that act as an enhanced version of Inquisitors. They are exclusive to the Rise of the Giant DLC.

Behavior
Arbiters fire a formation of five bolts in a wide spread instead of just one with at least one of them being aimed at the player.

When killed, the Arbiter drops a grenade which explodes and fires bolts in a hexagonal pattern, though it otherwise behaves like a normal grenade.

Strategy
To avoid getting hit, it is advised to bait them individually into attacking and parrying their attacks. Despite firing multiple projectiles, only one of them can effectively hit the player at range, making them similar to Inquisitors in a sense.

When wielding an off-color shield, however, parrying is less effective. Another safe option is to use the Homunculus rune to slowly kill them, as the range of this rune is larger than the Arbiter's detection field. In situations where neither of these approaches are possible (e.g. no shield, cursed), one can try to bait them on one side of the screen and quickly kill them from behind while they are firing at their previous location.

Elite Arbiters are ironically often easier to deal with than normal ones since they teleport and can be lured away. A notable exception to this is when an Elite Arbiter spawns with the electric cage ability, which makes it particularly hard to kill without getting damaged.

Trivia

 * Before v1.3, the Update the 13th, Arbiters were common enemies in most biomes at 3+ BSC. However, this resulted in excessive projectile spam and thus they removed and replaced them with Rampagers.