Storm Diver

There is no summon item and no way to meet one early. Divers exist only while the Lunar Events are running, which means the Lunatic Cultist is already dead, and they appear only in the ground the Vortex pillar has claimed. Bring the pillar down and they stop with it.

Treat it as a flying shotgun. The jetpack lets it climb to whatever height you picked instead of leaving it stuck on the ground, and it fires tight cones that hurt most when you are level with it. Current versions move faster, spread wider, open up sooner and shoot far more often than they used to, and one round in each burst is locked onto you no matter how you dodge. A short flash goes off just before it fires, which is your cue to break line of sight rather than trade.

One diver is survivable. Divers plus an Alien Queen is why the Vortex pillar has its reputation. Once the queen distorts you and you are pinned at a fixed height with nowhere to drop to, a diver simply floats up level with your face and empties into you. Kill queens on sight, and keep a hook or some other way of regaining vertical control before you push in.