Staff of the Frost Hydra

It anchors to whatever solid ground sits under your cursor, so you cannot hang one in open air. That means deciding where the turret goes while you are building the arena, not mid dodge. Give it a clear line down the lane enemies arrive from, because its shots stop at terrain.

Stacking several looks like more damage and often is not. Their shots share the same invincibility window on a target, so two of them firing at the same enemy waste hits on frames the other already used. If you do run more than one, spread them so they cover separate approaches instead of overlapping on the same spot.

Each shot punches through a couple of bodies before it gives out, with less bite on every extra one, so it does its best work on a line of enemies funneling toward you rather than on a single tank. The chill it leaves behind is real chip damage on top, which matters more over a long fight than in a burst. It does nothing on contact, so treat it as a turret you park and forget, never as a blocker.